Animal The Definitive Visual Guide

INSECTS 549

Life cycles EGG EGG NYMPH EGG pupa
wings NYMPH larva goes protected
Insects begin life as an egg. However, once a young appear through inside cell
insect hatches, it may follow one of several routes as buds several or cocoon
to adulthood (see right), varying from a simple series molts
of molts to a complete physical transformation of its
body parts. The length of each stage varies greatly NYMPH
between species. For example, a few species of
North American cicadas take 17 years to reach nymph grows NYMPH
adulthood, while some fruit flies may take less than gradually
2 weeks to mature. Once insects reach sexual larger
maturity, they begin to mate. Courtship displays
may involve the production of sexual odors, sounds, ADULT ADULT LARVA PUPA ADULT
and even light displays. In almost all insects,
fertilization is internal (see pp.30 – 1). The fertilized AMETABOLOUS DEVELOPMENT INCOMPLETE METAMORPHOSIS COMPLETE METAMORPHOSIS
eggs are usually laid close to a source of food. In some winged insects, such as
In some wingless insects, there is grasshoppers, the change from the In other winged insects, the immature
However, in parasitic species, they may be laid little difference in form between young immature stages (nymphs) to the adult is stages (larvae) molt several times. During
either on or inside the body of a host animal. and adults. The nymph develops by gradual. Nymphs look similar to adults but the last molt, the larvae pupate and the
shedding its exoskeleton, growing have no wings or reproductive organs. larval tissues are transformed into adult
larger after each molt. structures.

MIGRATION I N V E R T E B R AT E S

Many insects survive low temperatures by becoming
dormant. However, some of the larger winged insects are
capable of migrating over great distances to avoid winter
cold. One of the most celebrated examples is the monarch
butterfly (shown here). Each year, tens of millions of
monarchs travel up to 2,500 miles (4,000 km) from
Canada and the eastern United States to winter in
roosting sites in California and Mexico.

muscle attached DIRECT AND INDIRECT
to wing
WING CONTROL
muscles
Flight and wings contracted muscles Winged insects use various
relaxed mechanisms to control their
Insects were the first animals to evolve the power of flight, DIRECT WING CONTROL wings. Some control them
a development that made it easier for them to evade predators muscles
and to find food and mates efficiently. An insect’s wings, which relaxed directly, using muscles attached
are made of cuticle, are hinged to the thorax. Most insects thorax changes
have 2 pairs of wings. These are usually hooked together, but shape between to the wing bases to produce
in some species, such as dragonflies, they beat alternately, wingbeats
which improves maneuverability. True flies are the only insects the upstroke. Other insects TAKING OFF
that have one pair of wings; they are also the most agile fliers, INDIRECT WING CONTROL
capable of flying backward, sideways, and even upside down. move their wings up and down Beetles protect their delicate
Almost all flying insects can fold their wings, which means that hindwings under tough,
when they are not flying they can squeeze into small spaces, by changing the shape of the caselike forewings (elytra). It
such as crevices in bark or gaps under stones. takes a little time for a beetle
thorax. Insects that use this to lift its elytra and unfold the
hindwings before taking off.
muscles indirect control mechanism If the air is cold, many insects
contracted usually beat their wings more vibrate their flight muscles
to warm them up.
quickly (100 – 400 times per

second) than those that use

direct control (usually about

50 times per second).

550 ARTHROPODS

NON-INSECT HEXAPODS Class Protura

Class Collembola Proturans

Springtails Like springtails, proturans are sometimes found in leaf litter, but
most species live in the soil. These often microscopic animals do not
Although small and easily overlooked, springtails are present in have eyes, tails (cerci), or antennae, and instead they use their front
vast numbers in grassland, leaf litter, and soil. On the underside of the legs as sensory organs. Their mouthparts, which can both pierce and
abdomen, they have a ventral tube that allows them to regulate water suck, are kept in a pouch and are pushed out during feeding. There
and grip smooth surfaces, and a fork-shaped jumping organ (furcula), are 7 families of proturans, containing about 760 species.
which can be released like a spring to flick them away from predators.
There are 32 families (about 8,100 species) of springtails.

Family Poduridae Family Sminthuridae Family Eosentomidae and fungi. The eggs, laid in soil or leaf
litter, are spherical and have patterns
Water springtail Globular springtails Eosentomids or warts on them. Larvae are identical
to adults, but smaller.
Occurrence 4 species in the Northern Hemisphere; on Occurrence 245 spp. worldwide; in leaf litter, fungal Occurrence 340 spp. worldwide; in soil, leaf litter,
the surface of freshwater ditches, ponds, canals, bogs fruiting bodies on water surfaces, in caves mosses, humus, decaying wood

The most common and widespread Also known as garden springtails, these These pale and soft-bodied hexapods EOSENTOMON DELICATUM
species of this family, Podura aquatica, hexapods are 1⁄32 – 1⁄8 in (1 – 3 mm) in are 1⁄64 – 1⁄16 in (0.5 – 2 mm) long, and This often abundant species is native to Europe,
is up to 1⁄16 in (2 mm) long. It varies from length. Ranging from pale to dark brown have a conical head and an elongated although the genus is found all over the world.
brown or reddish brown to dark blue or or green, they have almost spherical body. They eat dead organic matter It lives in soil, especially chalky soil.
almost black. The furcula is quite flat bodies. The long, elbowed male antennae
I N V E R T E B R AT E S and long, and reaches the abdominal in many species are designed to hold the Class Diplura
ventral tube, enabling the springtail to female during mating. Eggs are laid in
cling to the water’s surface and jump small batches in soil, and development Diplurans
effectively. A scavenger, it feeds on to sexual maturity may take as little as
small, floating particles of food. Its eggs one month. Several species of these These blind, elongated, and soft-bodied hexapods are
are laid among vegetation in or around herbivores, such as Sminthurus viridis, sometimes called two-tailed bristletails due to their 2 terminal
water bodies. are pests of crop seedlings. cerci. They have a large, distinct head and biting, eversible
mouthparts. There are 8 families and about 975 species.

Family Japygidae forcepslike cerci which

Japygids are used to catch small

Occurrence 408 spp. worldwide; in soil arthropod prey. Eggs are

laid in batches in soil. long,
slender
body

PODURA AQUATICA SMINTHURIDES AQUATICUS These species are slender-bodied and HOLJAPYX DIVERSIUNGUIS
This abundant springtail is well adapted to life This tiny hexapod—only 1⁄16 in (2mm) long—is pale, ranging in length from 1⁄4 – 11⁄4 in Also called the slender dipluran,
on water. It may gather in such numbers on common on the surface of ponds, but does not (0.6 – 3 cm). The end of the abdomen this common North American
freshwater surfaces that the water appears dark. flock in such large numbers as the water springtail. carries a pair of distinctive, tough, species has stout, terminal
cerci. Its abdominal segments
are pale around the edges. cerci

INSECTS

Order Archaeognatha Order Thysanura

Bristletails Silverfish

Bristletails are wingless insects that look hump backed in side view. Distinguished from bristletails by their widely separated eyes, and
They have simple mouthparts, large eyes that touch each other, and 3 3 equally sized tails (cerci), silverfish have elongated, flattened bodies,
tails (cerci), the middle being the longest. Like silverfish, they do not often covered in silvery scales. There are about 570 species in 6
undergo metamorphosis. There are about 470 species in 2 families. families; some kinds are a familiar sight in houses.

Family Machilidae on algae, lichen, and plant debris. Eggs Family Lepismatidae fertilization is indirect. Eggs are laid
are laid in small batches in crevices, in small batches in cracks or crevices.
Jumping bristletails and the young mature in 2 years. They Lepismatids Domestic species feed on flour, damp
may live up to 4 years. textiles, wallpaper paste, and book
Occurrence 333 spp. worldwide; under stones, in leaf Occurrence 295 spp. worldwide, especially in warmer bindings. Lepismatids may live
litter, decaying vegetation regions; in tree canopies, caves, human dwellings up to 4 years.

These species are elongated and PETROBIUS MARITIMUS Lepismatids are brownish, nocturnal LEPISMA SACCHARINA
covered with patterns of drab brown This fast-running insect lives on rocky shorelines in insects with compound eyes but no The common silverfish emerges only at night,
or dark gray scales. Up to 3⁄8 in (1.2 cm) the Northern Hemisphere, often in large numbers. ocelli. They are 5⁄16 – 3⁄4 in (0.8 – 2 cm) prefers damp places, and can be found in
long, many can run and jump. They feed long. Courtship is simple, and kitchens, bathrooms, and basements worldwide.

INSECTS 551

Order Ephemeroptera Family Ephemeridae eggs, which they drop directly into
water. The nymphs burrow into the silt
Mayflies Common burrowing at the bottom of the water, using their
mayflies toothlike mandibles, and eat organic
The most primitive winged insects, mayflies are unique in undergoing material present in the silt. Adults do
a final molt after their wings have formed. Their underwater nymphs Occurrence 96 spp. worldwide except Australia; in and not feed. Artificial flies used in trout
live for 2 – 3 years, but adults do not feed, and often live for just one on vegetation around freshwater fishing are modeled on these mayflies.
day. There are about 3,000 species in 25 families.
large, veined,
Family Siphlonuridae triangular forewings

Primitive minnow typically large These are large mayflies, 3⁄8 – 11⁄2 in
mayflies hindwings (1 – 3.4 cm) long, with clear or brownish,
held upright rarely dark-spotted, triangular wings
Occurrence 126 spp. worldwide, but mainly in the and 2 or 3 long tails at the end of the
Northern Hemisphere; mostly in and near running water abdomen. Females lay thousands of small
hindwings

These mayflies have a wingspan of up to SIPHLONURUS LACTUSTRIS EPHEMERA DANICA 3 tails
2 in (5 cm). Nymphs are agile swimmers Anglers call this species the Also known as the greendrake, this is a large, of equal
and, when grown, pull themselves out of summer mayfly. It is one of widespread, European species. It breeds in length
the water onto a stone or stem. the first to colonize a new rivers and lakes with sandy or silty bottoms.
water course and is tolerant
of acidic water.

Order Odonata Family Coenagrionidae thoracic narrow wings I N V E R T E B R AT E S
segments folded above
Damselflies and dragonflies Narrow-winged angled body
damselflies backward
With their large eyes and superb flying ability, these
insects are highly effective aerial predators. Damselflies Occurrence 1,142 spp. worldwide, especially in temperate long abdomen
are slender, and tend to rest with wings folded, regions; in ponds, bogs, streams, brackish water COENAGRION PUELLA
while the stouter dragonflies rest with wings The azure damselfly is
held out. There are about 5,600 species, in 32 common in small ponds in
families. All start life as aquatic nymphs. Europe. Typical of the family,
the male tends to be more brightly
Family Aeshnidae ANAX These slender-bodied damselflies colored than the gray or greenish
IMPERATOR mostly have a wingspan of 3⁄4 – 13⁄4 in female (shown above).
Darners Found in parts of (2 – 4.5 cm). Females make slits in
Europe and Asia, the adult aquatic plants and lay eggs in them.
Occurrence 444 spp. worldwide; in and near still water, emperor dragonfly is a strong flier Nymphs hunt on underwater plants.
ponds, swamps with vegetation often seen hunting far from water.
Family Lestidae
hairy thorax Family Libellulidae
Stalk-winged
Also known as hawkers, darners are damselflies Common skimmers
some of the biggest, most powerful
dragonflies, with a wingspan of mostly Occurrence 152 spp. worldwide; in swampy or boggy Occurrence 986 spp. worldwide; in forests near
21⁄2 – 31⁄2 in (6.5 – 9 cm). Their large eyes places, pools, lakes, slow-flowing streams slow-flowing streams, ponds, bogs
touch on top of the head. Males hold
a territory and patrol it regularly, while long long, thin
females cut slits in plants to lay their abdomen pterostigma
eggs. Their nymphs are large and well
camouflaged, and hunt animals as BRACHYTRON Also known as darters due to their
large as tadpoles and young fish. PRATENSE unpredictable flight pattern, these
The adult hairy dragonfly typically emerges in stout-bodied, often colorful, insects
pterostigma May, flying low, with a characteristic zigzag path. Also called spread-winged damselflies, have a wingspan of mostly 13⁄4 – 3 in
these insects have sturdy, bright blue (4.5 – 7.5 cm). The broad, flat abdomen
large eyes or green bodies, with a metallic sheen. makes them highly maneuverable.
meet on top At rest they adopt a vertical pose with Females hover over water
of head the head up and the wings, spanning and dip down to release
11⁄4 – 3 in (3 – 7.5 cm), held out. Males their eggs. Nymphs hunt
have forceps-shaped claspers at the for prey in mud and debris.
end of the abdomen. Females
lay eggs inside the aerial parts large eyes touch dark wing
of aquatic plants. one another bases

AESHNA CYANEA wings held stalklike black,
Found in the lakes and outstretched wing bases rectangular
ponds of Europe, the wings held pterostigma
southern hawker is a AESHNA MIXTA outwards
large, summer species. The migrant hawker, widespread in central and LIBELLULA DEPRESSA
Males attack other males southern Europe, follows along a regular beat to LESTES SPONSA The broad-bodied chaser flat, broad
in their territory on sight. catch prey. It flies in summer and fall, and often The emerald damselfly is found in is a European species. abdomen
migrates across Europe in large numbers. Europe and Asia. It has a dark green Adults fly over ponds and
body and inhabits canals, ponds, and lakes. lakes, in June and July.

552 ARTHROPODS

Order Orthoptera Family Gryllotalpidae Family Rhaphidophoridae

Crickets and grasshoppers Mole crickets Cave crickets

With over 25,000 species in 40 families, crickets and grasshoppers are Occurrence 105 spp. nearly worldwide; burrowing Occurrence 594 spp. widespread, especially in warmer
widespread in all but the coldest parts of the world. Most species have in damp sand or soil near streams, ponds, lakes regions; in caves, humid areas, under logs and stones
large wings—the front pair, or tegmina, being tough and leathery—but
instead of flying away from danger, they often jump away on their Like mammalian moles, these crickets Squat, hump backed, and wingless,
powerful hindlegs. They have chewing mouthparts, but their diets vary: are stout and covered with short, velvety cave crickets are 1⁄2 – 11⁄2 in (1.3 – 3.8 cm)
crickets, katydids, and their relatives (suborder Ensifera) are predators hairs. Measuring 3⁄4 – 13⁄4 in (2 – 4.5 cm) in long. They have long hindlegs and even
or omnivores, while grasshoppers and locusts (suborder Caelifera) are length, they have short, broad, toothed longer antennae that help detect
entirely vegetarian. All species undergo incomplete metamorphosis, front legs used for digging. Females dig predators. These crickets are drab
and most adult males stridulate, or “sing,” to attract mates. brown or gray in color. Some cave-
chambers in the soil to lay their eggs; adapted species have reduced eyes
Family Acrididae drab males make special burrows to and soft bodies, and lay their eggs in
coloration amplify their songs, which can be heard cave-floor debris. Nymphs start
Grasshoppers up to 1 mile (1.5 km) away. Adults and searching for food as soon as they
nymphs eat parts of plants as well as hatch; some scavenge, while others
Occurrence 10,500 spp. worldwide; on ground, small prey, feeding underground during catch living prey.
in vegetation the day and on the surface at night.

Grasshoppers are 3⁄8 – 31⁄4 in (1 – 8 cm) CHORTHIPPUS BRUNNEUS distinctive stout hind long hindlegs
long and have camouflage coloring and The common field grasshopper inhabits humped back femora adapted for
patterning. However, some have brightly grassland from Northern Europe to Spain and long jumping
colored bodies, or wing bands, to warn Italy. It has a very distinctive song—a series antennae
off predators. Some also produce of chirps repeated every 2 seconds or so.
noxious chemicals. The antennae are
I N V E R T E B R AT E S always short. Males sing during the day saddle-shaped short antennae
to attract mates. Females are nearly pronotum typical of family
always larger than males and
do not have a conspicuous GRYLLOTALPA GRYLLOTALPA PHAEOPHILACRIS GEERTSI
ovipositor. After mating, The European mole cricket is attracted This African cave cricket is found only in the
they lay egg pods to lights after dark. It uses its front legs for Democratic Republic of Congo.
containing 15 – 100 eggs digging, and hindlegs for pushing soil along
in the ground and protect burrows. It can be a crop pest.
them by secreting a foamy
substance around them. Family Tettigoniidae very long uneven wing
Grasshoppers are agricultural antennae outline to
pests; species that periodically Katydids brown, leaflike mimic leaves
form nomadic swarms—known color
as locusts—destroy crops in Occurrence 6,728 spp. worldwide, mainly in tropical
some parts of the world. regions; on vegetation

strong hindlegs toughened STENOBOTHRUS
for jumping forewings LINEATUS
on land, and The stripe-winged
steering grasshopper lives in dry, Also known as bush crickets, these sickle-shaped ovipositor
in flight sunny grassland and pastures insects get their name from a North OMMATOPTERA PICTIFOLIA
in Europe. It has a high-pitched, American species whose song sounds Found in Brazil, this bush cricket
alternately loud and soft, song. like “kate-she did.” They measure lives in trees and bushes, and is
1⁄2 – 3 in (1.5 – 7.5 cm) in length and are an excellent mimic of dead leaves.
large, SCHISTOCERCA GREGARIA brown or green, usually with big wings
membranous Found from Africa to India, the desert locust is that slope over their sides. Most distinctive
hindwings 21⁄4 in (6cm) long. It has been a crop pest since species mimic leaves or bark. ovipositor
agriculture first developed. Swarms of up to They may also flash bright,
50 billion individuals move with prevailing hindwing colors to startle
winds and can devour up to 110,231 tons predators. Males sing using
(100,000 tonnes) of food in a day. a file and scraper system at
the base of the forewings.
Family Gryllidae wings folded rounded Females lay eggs in plants or
flat over body head soil. Most katydids feed and
True crickets sing only at night.
long
Occurrence 4,693 spp. worldwide; on ground, under antennae very short
stones, in leaf litter, on trees wing in
both sexes

cerci strong long, MECONEMA
hindlegs segmented THALASSINUM
True crickets are 3⁄16 – 2 in (0.5 – 5 cm) antennae The oak bush cricket can
long, with slightly flattened bodies. BRACHYTRUPES SP. saberlike LEPTOPHYES PUNCTATISSIMA be found in Europe, mostly
Some species have loud, chirping Sometimes called tobacco crickets, these ovipositor The speckled bush cricket is in oak woodland. It is mainly
songs, and are kept as pets. Most species are distributed across the African distributed across Europe, nocturnal and flies readily.
true crickets, except the carnivorous savanna. Relatives include pests that attack and can be found in bushes, Males signal to females by
tree crickets, are either plant eaters tea, tobacco, and cotton crops. trees, and grassland. drumming their hindlegs
or scavengers. against leaf surfaces.

INSECTS 553

Order Plecoptera Order Phasmatodea

Stoneflies Stick and leaf insects

Stoneflies are flat, slender-bodied insects that start life in water, These strikingly sticklike or leaflike insects live and feed on plants,
developing by incomplete metamorphosis. Adults have 2 pairs of
membranous wings, but are reluctant fliers. Most are short-lived, and use their remarkably effective camouflage to avoid being eaten.
often not feeding at all. There are about 3,000 species in 19 families.
The males—which are rare in some species—have wings, but the

long females are frequently wingless. They develop by short
antennae incomplete metamorphosis, and are usually antennae
nocturnal. There are about 2,500 species in 3 families.
Family Perlidae brown
coloration Family Phasmatidae leaflike
Common stoneflies expansions on
Stick insects leg segments
Occurrence 933 spp. worldwide except Australia;
in lakes, rivers, vegetation near running water Occurrence 2,450 spp. mainly in warm regions; among
vegetation or foliage of trees and shrubs

As adults, common stoneflies are weak DINOCRAS long EXTATOSOMA TIARATUM
fliers, and often rest on stones close to the CEPHALOTES cerci
water’s edge. They are 3⁄8 – 2 in (1 – 4.8 cm) This European species
long, and are colored in shades of brown is found near running water. Also called walking sticks, these Native to Australasia, Macleay’s
or yellow. The adults do not feed, but the The nymphs may molt more than 30 insects can adopt a twiglike posture spectre is one of the many
nymphs are often carnivorous. times and take up to 5 years to mature. that camouflages them superbly; species that is often raised
some can even sway in the breeze in captivity on bramble leaves.
to blend with the background. Stick The female (shown right) is
insects vary from 1 – 241⁄2 in (2.5 to wingless, larger than the male,
621⁄4 cm) in length and have a spiny or and lays a dozen eggs every
warty, brown or green body, with short, day of her adult life, flicking
Order Grylloblattodea tough front wings to protect the large, them away with
membranous hindwings. Some species her abdomen. spiny, leaflike
Rock crawlers are wingless. When threatened, some expansions at
stick insects adopt a scorpionlike sides of abdomen
posture, while others flash their
Rock crawlers were first discovered in the Canadian Rockies in wing colors, or give off noxious curve allows square I N V E R T E B R AT E S
1913. Forming one family of 30 species, these small, wingless insects chemicals. If attacked, they can front legs to head
are adapted to cold conditions, and eat dead, windblown, or torpid shed their legs, which soon grow be held at side
prey, moss, and other plant matter. Metamorphosis is incomplete. back. In many species, males occur of head
either rarely or not at all, and the
flat head females typically scatter their
seedlike eggs on the ground.
Family Grylloblattidae simple, cylindrical long
abdomen slender body metathorax
Rock crawlers
distinctive spined, ridged
Occurrence 30 spp. in cooler regions of the Northern cerci ovipositor leg segments
Hemisphere; in limestone caves, decaying wood
PHARNACIA SP.
Mainly nocturnal, rock crawlers, or ovipositor shorter pale, Found in India, this genus
ice crawlers, are 3⁄8 – 11⁄4 in (1.2 – 3 cm) than cerci segmented contains extremely slender insects. The
long, have small eyes, and biting antennae females, like the one shown here, are
mouthparts. Females may lay eggs wingless. They can hold their legs close to their
over 2 months after mating; nymphs GRYLLOBLATTA CAMPODEIFORMIS body to enhance their twiglike appearance.
take years to develop. The northern rock crawler is found at high
altitudes in the USA and Canada. It lives
among rocks near glaciers.

Order Dermaptera Family Phylliidae the transparent hindwings. The
antennae are short and smooth in
Earwigs Leaf insects females, and long and slightly hairy
in males. The eggs are seedlike and are
This order contains 11 families (about 1,900 species) of scavenging Occurrence 30 spp. in Mauritius, Seychelles, Southeast dropped on the ground. Because
or plant-eating insects with characteristic abdominal “pincers.” Most Asia, Australasia; on various plants in well-vegetated of their odd appearance, leaf insects
have short front wings, and fan-shaped hindwings that can be folded. areas are bred as pets all over the world.
Maternal care is well developed. Metamorphosis is incomplete.
Flat, expanded abdomens, extended long, slightly
Family Forficulidae hairy antennae
leg segments, and brown or green small forewings
Common earwigs
coloring all give these PHYLLIUM BIOCULATUM
Occurrence 450 spp. worldwide; in leaf litter and soil, Found in the foliage and
under bark or in crevices insects an uncanny trees of Southeast Asia,
the Javanese leaf insect
resemblance to is often bred as an unusual
pet. It is easy to rear as long
leaves. The disguise as it is kept in warm conditions.

is helped further by

blotches of color and

texture, and an ability

to sway in the breeze.

Some species specialize

These species are 3⁄8 – 1 in (1.2 – 2.5 cm) in looking like dead, transparent
long and usually dark brown. Two wrinkled leaves. Leaf hindwings
forcepslike appendages are straighter in
females and curved in males. Females insects range from
guard their eggs and lick them clean.
FORFICULA AURICULARIA 11⁄4 – 41⁄4 in (3 to 11 cm) marks on
The common earwig, now found worldwide, is in length. At rest, their abdomen mimic
a pest of vegetables, cereals, fruit, and flowers. veined forewings cover holes in leaves

I N V E R T E B R AT E S 554

INSECTS 555

THREAT DISPLAY Order Mantodea
When disturbed, mantids like
this flower mantid, Creobotra Mantids
elegans, often rear up into
a defensive pose to display The common name “praying” mantid is derived from the distinctive
their vivid coloration. In way in which mantids hold their front legs up and together, as if in
addition to using its excellent prayer. Although variable in shape, mantids are distinguished by their
eyesight, the mantid avoids triangular heads and large eyes—they are the only insects able to turn
attack from bats by using an their head around to look behind them—and an elongated prothorax
ultrasonic ear on the thorax with the front pair of legs distinctively modified for catching live prey.
between the middle legs. Most mantids are diurnal and eat a large range of arthropods and,
occasionally, even vertebrates such as frogs and lizards. Mantids
reproduce by laying eggs in a papery or foamlike egg case, which, in
some species, is guarded by the female. There are over 2,300 species.

Family Hymenopodidae that resemble leaves. The forewings of I N V E R T E B R AT E S
flower mantids may have colored bands
Flower mantids or spirals, or circular marks that look like
eyespots. In some species, the colored
Occurrence 290 spp. in tropical regions, all around the markings on the front wings can be
world except Australia; on a wide variety of vegetation asymmetrical. The wings of the female
flower mantid are sometimes shorter
Vivid coloration, including bright reds and than those of the male. Young nymphs
greens (see left), allows these species to are immediately predatory and are able
blend in perfectly with the plants on to tackle prey as soon as their cuticles
which they rest, awaiting the arrival of have hardened. As well as having an
prey. Some parts of the body, such as ultrasonic ear, used to detect predators,
the legs, often have broad extensions some species have a second ear that is
responsive to much lower frequencies,
but its function is unknown.

threadlike Family Mantidae resemblance to leaves and twigs. Unlike
antennae families such as the flower mantids, the
Common praying wings of common praying mantids are
large, mantids seldom patterned, although they may
forward- have wingspots. Females often have
facing eyes Occurrence 1,101 spp. in warmer regions, all around smaller wings than males, and some
the world; on any vegetation where there is ample prey lack wings entirely. Some species
of common praying mantids can grow
Most praying mantids belong to this up to 6 in (15 cm) in length, and the
family, and many members vary little larger species are known to prey on
in appearance. Most have green small reptiles, salamanders, and frogs.

elongated or brown coloration and a close head and large female
prothorax leaflike, part of
veined wings thorax eaten

raptorial
front legs

slender ELEGANT PROFILE DANGEROUS ENCOUNTERS
legs The common praying mantid’s forward- Female common praying mantids are famed
facing eyes give it true binocular vision, for eating the male after mating (see above).
STEALTHY HUNTER allowing it to calculate distances accurately. However, although mating can be dangerous for
This ability, together with its extendable front smaller individuals, males are usually cautious and
legs, makes it an effective hunter. seldom get eaten by their partner in the wild.

123 4

LYING IN WAIT THE POUNCE THE CAPTURE ALL OVER IN SECONDS
Clasped in a strong grip, the helpless fly has
The mantid lies patiently in wait for a potential As an unsuspecting fly comes within range, the At full stretch, the mantid seizes and impales its no means of escape. Having retreated back
meal. Perching on the end of a stick, forelegs mantid acts quickly. It launches itself at its victim, victim with its spiky legs before it is even aware to its stick, the mantid begins to eat its prey.
together, it focuses on a likely landing site for prey. lunging forward and reaching out its long forelegs. of the mantid’s presence.

556 ARTHROPODS

Order Blattodea Family Blattellidae Family Blattidae

Cockroaches Blattellids Common cockroaches

Cockroaches are leathery insects, typically with oval and flattened Occurrence 2,240 spp. worldwide in warmer areas; Occurrence 652 spp. mainly in tropical and subtropical
bodies that enable them to squeeze through tight spaces in search in woodland litter, debris, garbage dumps, buildings regions; common in warehouses, sewers, garbage
of food or to escape predators. They are sensitive to vibration and dumps
can quickly flee from danger. The head is often covered by a shieldlike Many of these fully winged species are
pronotum and there are generally 2 pairs of wings. The order Blattodea pale brown but a few are olive-green. Most species of common cockroaches
comprises 9 families and about 4,600 species, of which less than Their body length varies from 5⁄16 to are brown or reddish or blackish brown
1 percent are pests; the rest are useful scavengers in many habitats. as long as 4 in (0.8 – 10 cm). Adults and with markings. They are 3⁄4 – 13⁄4 in
The pest species thrive in warm conditions and where there is poor nymphs are scavengers. Females carry (2 – 4.5 cm) long, very active, and can
hygiene and sanitation, and can carry many disease-causing their egg cases, which protrude from run very fast or fly. Some species emit
organisms on their bodies. their bodies, until the eggs are about repellent chemicals that can cause skin
to hatch. Thousands of eggs may be rashes. Females can produce up to 50
Adults may produce sexual pheromones to attract mates. The produced in a lifetime. egg cases, each containing 12 – 14
females lay up to 50 eggs in 2 rows surrounded by tough, protective eggs, which are stuck to concealed
egg cases called oothecae. Metamorphosis is incomplete. long, threadlike surfaces. Both adults and nymphs are
antennae nocturnal and saprophagous.
Family Blaberidae are fully extruded from the end of the
abdomen, rotated, and then drawn head pointed
Live-bearing back inside to be brooded within the downwards
cockroaches body of the female. Adults and nymphs
are mainly saprophagous or eat dung.
Occurrence 1,189 spp. in tropical regions; in caves,
underground leathery thoracic humps
abdomen used in male-to-
male combat

I N V E R T E B R AT E S These large insects, usually measuring short, thick legs males and slender
1 – 21⁄4 in (2.5 – 6 cm) in length, often GROMPHADORHINA PORTENTOSA females fully legs
have well-developed, pale brown wings Better known as the Madagascan hissing winged
with dark markings. In many species, cockroach, this insect is 21⁄4 – 31⁄4 in (6 – 8 cm) MEGALOBLATTA LONGIPENNIS protruding egg
however, the females are wingless and long, and startles predators by squeezing air The long-winged great cockroach from Peru, case
burrow under wood and stones. The out of its spiracles to produce a loud hiss. Ecuador, and Panama is the largest winged BLATTA ORIENTALIS
pronotum may be very wide. During cockroach in the world. It has a wingspan The oriental cockroach is a common domestic
courtship, some species use sounds of up to 8 in (20 cm). pest. Like many species, it has spread from
to communicate with a mate. All its native region by traveling on board ships.
species are ovoviviparous and give
birth to live young. The egg sacs

Order Isoptera Family Termitidae

Termites Higher termites

Like ants (see p.576)—with which they are sometimes confused— Occurrence 2,021 spp. worldwide; in trees, soil,
termites are social insects, living in colonies that can be over a million underground
strong. There are about 3,000 species, in 7 families, and most live
in the tropics, where they build impressive nests. They are usually Three-quarters of the world’s termite
pale and soft, with chewing mouthparts and short antennae, but
their body form varies with their role in the colony. Workers are small, species belong to this family. Highly GLOBITERMES SULPHUREUS
while soldiers have large heads and jaws. Queens, which lay all the This Southeast Asian pest makes thick-walled
colony’s eggs, can be as big as a human finger. Some termites feed variable, both in appearance and habits, nests partly underground. The nests’ soldiers
on wood or plants, but others eat fungi that they raise in underground can “explode” to cover intruders in a sticky fluid.
“gardens.” Although important in food chains as nutrient recyclers, they range in length from 5⁄32 – 1⁄2 in TRINERVITERMES TRINERVOIDES
many are destructive pests. Metamorphosis is incomplete. The snouted harvester termite lives in pastures
(4 – 14 mm). Queens are much bigger in central and southern Africa. It is eaten by
the aardwolf (see p.209)—an animal that has
than the workers and soldiers, and may evolved immunity to its defensive secretions.

produce thousands of eggs a day.

Family Rhinotermitidae of the world are highly damaging pests. Nests vary from small structures built
Generally cream or light brown, they are
Subterranean typically 1⁄4 – 5⁄16 in (6 – 8 mm) long. in trees, to vast earthen towers, with
termites
underground “fungus gardens.” Many

species are crop pests. broad
head
MACROTERMES SP.
Termites in this abundant
Occurrence 360 spp. worldwide in warmer regions; African genus often form
in soil or in damp wood touching ground giant colonies. At certain

times of the year, winged
reproductives fly
off to found
As adults and nymphs, subterranean new colonies.
termites feed mainly on wood, digesting
it with the help of microbes that they RETICULITERMES LUCIFUGUS large, pale
harbor in their intestines. They are This termite has distinctive antennae. It makes its wings
voracious feeders, and in warm parts nest under the ground, inside damp wood, and is
commonly found throughout southern Europe.

INSECTS 557

Order Embioptera Order Phthiraptera

Web-spinners Parasitic lice

This relatively small order consists of 11 families and only about 400 Flattened and wingless, the 5,200 species (in 24 families) of parasitic
species. Web-spinners are gregarious, and live in soil, leaf litter, and lice are ectoparasites, living permanently on the bodies of birds and
under bark. They make extensive protective tunnels, using the silk mammals without killing them. The mouthparts are used to bite skin,
made by glands in their front tarsi. Metamorphosis is incomplete. fur, or feathers, or to suck blood. Different lice are linked with specific
hosts, and many are restricted to particular areas of the body. Parasitic
Family Clothodidae mandibles to hold onto the female lice develop by incomplete metamorphosis.
during mating. Females and nymphs
Clothodids are saprophagous. Females cover their Family Menoponidae Family Pediculidae
eggs with silk and detritus, and feed the
Occurrence 15 spp. worldwide in tropical and nymphs with pre-chewed food. Bird lice Human lice
subtropical regions; in soil, leaf litter, under bark
and stones Occurrence 1,153 spp. worldwide; on a variety of Occurrence 7 spp. worldwide; on humans, apes,
bird hosts monkeys

Clothodids are typically elongated ANTIPALURIA INTERMEDIA Bird lice are 1⁄32 – 1⁄4 in (1 – 6 mm) long, with Human lice are small, pale, and
insects with short legs. They are Seen here inside its silken nest, this species is a large and roughly triangular head, and elongated, measuring 1⁄16 – 1⁄4 in (2 – 6 mm)
3⁄16 – 3⁄4 in (0.5 – 2 cm) long, and have a native of Central America. biting mandibles. The abdomen is oval, in length, with short, strongly clawed
small eyes, segmented antennae, and and the legs are short and stout. Each legs for gripping onto their hosts. They
simple, biting mouthparts. As adults, leg has 2 claws. Adults and nymphs of have a narrow head and a pear-shaped,
males do not feed but use their most species feed on feather fragments flattened body. Adults and nymphs
but some also ingest blood and skin feed on blood. The human louse has
Order Zoraptera secretions. Eggs are glued in masses to 2 subspecies: the body louse, which I N V E R T E B R AT E S
the base of feathers. Some species, such glues its eggs to clothing, and the head
Angel insects as Menopon gallinae, or the shaft louse, louse, which glues its eggs (nits) to hair.
can be serious poultry pests. Outbreaks of head lice are common
These small, delicate, gregarious, termitelike insects make up among young schoolchildren. The
a single family of 43 species. They are light straw-yellow to dark broad body louse carries the
brown or blackish in color, with short, abdominal tails (cerci) and head organism that
unspecialized mouthparts. Metamorphosis is incomplete. causes typhus.
short,
Family Zorotypidae species give the females mating gifts stout legs pear-shaped,
in the form of secretions from glands in flattened body
Angel insects their heads; in other species, the males 2 claws
fight for mates by kicking each other. on each leg PEDICULUS
Occurrence 43 spp. worldwide in tropical and warm HUMANUS CAPITIS
temperate regions except Australia; in rotting wood, short, beadlike MENACANTHUS STRAMINEUS A female human head
sawdust stout legs segments The chicken body louse is a louse can lay 9 – 10 eggs
widespread species that lives on poultry, a day, fastening each
Angel insects are 1⁄16 – 1⁄8 in (2 – 3 mm) bringing about feather loss and infection. one separately to a hair.
long, with a distinctive triangular Once cemented in
head and a pair of antennae. The position, the eggs are
nymphs and adults eat fungal threads difficult to dislodge.
and small arthropods. Sexual behavior
may be complex: males of some cerci ZOROTYPUS HUBBARDI Family Pthiridae may lay 30 eggs in her lifetime, and uses
with one The rare Hubbard’s angel insect a waterproof glue to stick them singly to
segment is native to eastern and southern Pubic lice pubic hair. It takes 4 weeks for the eggs
North America. This slide- to mature into adults.
mounted specimen is stained red. Occurrence 2 spp. worldwide; wherever their hosts
(humans and gorillas) live PTHIRUS PUBIS
Order Psocoptera The pubic louse may be found in armpits
and beards as well as the groin. Although
Barklice and booklice unpleasant, it is not known to transmit disease.

The order Psocoptera comprises 41 families and 5,600 species Also known as crab lice, eye
of soft-bodied, drably colored insects. The head is large, with
bulging eyes, a bulbous forehead, and long, threadlike antennae. pubic lice have a squat, small head
Metamorphosis is incomplete, typically with 5 nymphal stages.
flattened body, 3⁄64 – 3⁄32 in

(1.5 – 2.5 mm) long. The middle

and hindlegs are especially antennae
stout and have very strong,

Family Liposcelididae or chew stored flour, cereals, or paper. enlarged claws for gripping
Eggs are laid in crevices in tree bark,
Liposcelid booklice leaf litter, and bird nests. The nymphs hair shafts. The nymphs and
look like small adults.
Occurrence 250 spp. worldwide; in dry leaf litter, under adults suck the host’s blood,
bark, in nests, inside buildings, in food stores
leaving bluish marks on the skin.

They move very slowly, often

hardly at all. A female

These insects have flattened bodies, LIPOSCELIS DECOLOR squat body strong, vicelike claws
with swollen femora on the hindlegs. Found in leaf litter and in a variety of stored, nymph for holding onto hair
Most species are wingless. The length dry produce, this widespread species can
of the body ranges from 1⁄64 – 3⁄64 in become a pest.
(0.5 – 1.5 mm). Some species gnaw on

558 ARTHROPODS

Order Hemiptera Family Aphididae tubes that emit a defensive secretion.
Reproduction is often parthenogenetic
Bugs Common aphids or only seasonally sexual.

Bugs vary in size from species a few millimeters long to giant Occurrence 2,250 spp. worldwide, especially MACROSIPHUM ALBIFRONS
aquatic predators large enough to catch fishes and frogs. They are in northern temperate regions; on most wild The American lupin aphid is a pest of garden
found all over the world, in every terrestrial habitat as well as in and cultivated plants flowers, both in North America and Europe. Here,
freshwater. The order comprises 134 families and 88,000 species. one female (top left) is giving birth.
There are 4 suborders: Coleorrhyncha, consisting of a single family; Their huge reproductive potential
Heteroptera or true bugs (including plant bugs); Auchenorrhyncha makes aphids among the most
(including treehoppers, lantern bugs, and cicadas); and Sternorrhyncha destructive of all plant-eating insects,
(including whiteflies and scale insects). All bugs have 2 pairs of wings; affecting almost all crop species by
in the Heteroptera, the front ones are typically larger and thickened. feeding and transmitting diseases. Also
The mouthparts, which form a long rostrum, or “beak,” pierce and called greenflies or blackflies, these are
suck, and many sap-sucking species are serious crop pests. pear-shaped, soft-bodied insects, mostly
Metamorphosis is incomplete. 3⁄16 in (5 mm) long, and typically green,
pink, black, or brown. The abdomen
Family Aleyrodidae usually has a pair of cornicles, short

Whiteflies

Occurrence 1,200 spp. worldwide, especially in warmer Family Belostomatidae curved tibiae
regions; on a wide range of plants, including crops with sharp
Giant water bugs claws for
seizing prey

These delicate, mothlike bugs are Occurrence 150 spp. worldwide, especially in tropical large eyes
1⁄32 – 1⁄8 in (1 – 3 mm) long. They carry and subtropical regions; in standing water, slow-moving
a pair of 7-segmented antennae, and streams
2 pairs of transparent, white, or mottled
I N V E R T E B R AT E S wings of similar size. Females lay their TRIALEURODES VAPORARIORUM Also known as electric light bugs due hairs on middle
eggs on tiny stalks on the undersides The greenhouse whitefly is a common pest of to their attraction to lights, this family and hindlegs
of leaves. Many of these plant sap- cucumbers and tomatoes grown under glass. contains the largest bugs, able to eat aid swimming
suckers are serious pests. It may also attack field crops in warm conditions. frogs and fishes. They have a brownish, LETHOCERUS GRANDIS
oval body that is 1⁄2 – 4in (1.5 – 10 cm) This widespread giant water
Family Cercopidae Family Cicadellidae long. The front legs are modified as bug is caught and eaten by
prey-capturing pincers. Uniquely among humans in certain parts of
Froghoppers Leafhoppers insects, females glue their eggs to the Southeast Asia.
male’s back, who then broods them.

Occurrence 2,400 spp. worldwide, especially in warmer Occurrence 16,000 spp. worldwide; almost anywhere
regions; on shrubs, trees, herbaceous plants with vegetation, abundant in agricultural habitats
Family Cicadidae

Cicadas

These squat, round-eyed, plant bugs Leafhoppers are typically slender-bodied Occurrence 2,500 spp. worldwide in warmer regions;
are very good jumpers. Many species and 1⁄8 – 3⁄4 in (0.3 – 2 cm) long. Many on suitable host trees or shrubs
have drab coloration but some are species are brown or green; some may
colored in bright red and black or yellow be brightly striped or spotted. Males Cicadas include some of the world’s
and black patterns. Body length ranges attract females with low-amplitude
from 3⁄16 – 3⁄4 in (0.5 to 2 cm). Eggs, up to courtship calls, which travel through noisiest insects, producing calls that
30 in some species, are laid in soil or in leaves and stems, instead of being
plant tissue. Nymphs feed on plant sap. carried through the air. Once a female can be heard up to 1 mile (1.5 km) CICADA ORNI
They surround themselves in foam, has mated, she lays hundreds of eggs away. The adults are usually dark brown This species, common in southern Europe and the
which hides them and stops them over a period of 6 – 8 weeks. Leafhoppers or green, with squat bodies 3⁄4 – 21⁄4 in Mediterranean, has a grayish bloom, clear front
from drying. are highly destructive pests, attacking (2.2 – 5.5 cm) long. They have short wings with 11 black spots, and a long rostrum.
many of the world’s staple crops, such
pronotum wider as rice, corn, cotton, and sugarcane. antennae, and prominent eyes set far The adults are eaten by birds such as jays.
than head
triangular head with apart. Only the males sing, using a pair short prominent eyes
distinctive, black markings of drumlike antennae
black and
red coloration green front tymbal organs
wings
located on
CICADELLA VIRIDIS
Widespread in Europe and Asia, the common the sides of the
green leafhopper can be a pest of fruit, rice,
wheat, and sugarcane. abdomen. Females

lay eggs by cutting slits

in plants; after hatching,

the nymphs feed on roots

underground. Some species

can live for up to 17 years. male’s abdomen hindwings smaller
membranous, yellow acts as resonator, than front wings
front wings to amplify songs PYCNA REPANDA
The Himalayan cicada
is commonly found
CERCOPIS VULNERATA ANGAMIANA AETHEREA resting and feeding
This froghopper inhabits Like all cicadas, this Indian among a variety
stout hindlegs grassy places and meadows cicada produces songs to signal of tree species, in
with spines in Europe and Asia.

aggression or to attract mates. forests and woodland.

INSECTS 559

Family Cimcidae Superfamily Coccoidea Family Fulgoridae

Bed bugs Scale insects Fulgorids

Occurrence 90 spp. worldwide; on bird and mammal Occurrence 7,000 spp. worldwide, especially in tropical Occurrence 800 spp. in tropical and subtropical
hosts, in nests, caves, crevices in buildings and subtropical regions; on all parts of many plants regions; mostly on trees and woody shrubs in
well-vegetated areas

These flat, oval, reddish brown bugs Scale insects are so highly adapted to a Many tropical fulgorids are notable for FULGORA SERVILLEI
are 5⁄32 – 3⁄8 in (4 – 12 mm) long, and have sap-sucking life that they hardly resemble their bizarrely shaped, bulbous heads, Found in the forests of South America, this
remnant front wings and no hindwings. insects at all. The females are often and are known as lantern bugs. Their species has a very enlarged head with tooth-
Their compound eyes have a small wingless and legless, and spend their eyes are located at the sides of the like markings. Like most species in the family,
number of facets. All bed bugs are blood adult lives permanently attached to head, above the antennae. The thorax it is a sap-sucker.
sucking, temporary ectoparasites that plants. Most are under 3⁄8 in (1 cm) long, is often quite large, as are the wings,
live on birds, bats, and even humans. with an oval body covered by a smooth which have cross veins. These sap- oddly cryptic
They live for 2 – 10 months depending or waxy scale. The males look very suckers are 5⁄16 – 4 in (0.8 – 10 cm) long shaped head coloring on
on feeding and temperature. Males different, and often have wings. Many and have eyespots on the hindwings that forewings
practice traumatic insemination, injecting can be flashed to deter predators. Adults
sperm by penetrating the female’s body scale insects reproduce rest and feed during the day and fly at
with a sharp sexual appendage. asexually, and can be night. Eggs are laid on host plants and
Females may lay more than 150 eggs prolific crop pests. covered by a frothy secretion, which
in their adult life, with 2 or 3 eggs laid hardens to protect them.
per day.
elongated
head

mealybugs PLANOCOCCUS CITRI large bright I N V E R T E B R AT E S
clustered The common citrus eyespots hindwings
under bud on hindwings PHRICTUS QUINQUEPARTITUS
CIMEX LECTULARIUS mealybug is a FULGORA LATERNARIA The wart-headed bug has colorful wings
The common bed bug feeds at night and senses pantropical pest Also called the lanternfly or peanut-headed bug, and an unusual head. It is found in woodland
the presence of a host using temperature, odor, that attacks coffee, this species has a bulbous head that was once and forests of Panama, Brazil, Colombia, and
and carbon dioxide concentration as cues. soy bean, and guava thought to glow. It occurs in South America Costa Rica.
crops. It attaches itself and the West Indies.
mainly to the plants’ roots,
but also to their stems.

Family Gerridae using ripple-sensitive hairs. Mating Family Membracidae Family Miridae
follows ripple courtship signals, and
Pond skaters eggs are laid on floating objects or Treehoppers Plant bugs
embedded in water plants.
Occurrence 500 spp. worldwide; in water bodies Occurrence 2,500 spp. worldwide, mainly in Occurrence 8,000 spp. worldwide; on all aerial parts of
ranging from pools, ponds, streams, rivers, and lakes, warmer regions; especially in understory layers a wide range of plants, including crops
to warm oceans in tropical forests

Also known as water-striders, these GERRIS SP. The large, distinctive pronotum, often Also known as capsid bugs, these
fast-moving bugs are 1⁄16 – 11⁄2 in These bugs are widespread and live on shaped like a thorn, gives this family the fragile, elongated or oval insects form
(0.2 – 3.5 cm) long, dark brown or black, water surfaces. Ripples made by prey attract alternative name of thorn bugs. These the largest family of true bugs. They
and covered with short, velvety hairs. the bugs, which move quickly to attack. plant sap-suckers are mostly green, show a great variety of colors and
The elongated body has short, stout brown, or brightly colored, measuring markings—some resemble ants—
front legs used for grasping prey, and 3⁄16 – 1⁄2 in (0.5 – 1.5 cm) in length. Female and are generally 1⁄16 – 1⁄2 in (2 – 16 mm)
long middle and hindlegs that help to treehoppers lay egg masses in slits long. Most are sap-suckers, but some
spread its weight over the water film. made in the host plant’s bark and, scavenge or hunt live prey. Plant bugs
These predatory bugs detect prey depending on the species, a single protect themselves by having cryptic
female may lay up to 300 eggs. The coloring, or by giving off
Family Hydrometridae at all. Water measurers are predators female frequently guards them until a noxious scent
and scavengers in all life stages, using they hatch. Ants protect many species when threatened.
Water measurers a spearing and sucking technique to in return for honeydew. Eggs are inserted
feed; they prefer dead or dying prey. inside plant tissues;
Occurrence 120 spp. worldwide; in standing water head tucked thorn- a female may lay a
bodies, on floating plants under shaped total of 30 – 100
body pronotum eggs during her
adult life. Many species
eyes far from long, threadlike are fruit and crop pests.
pronotum legs
oval body
Like pond skaters, water measurers, dark
also called marsh-treaders, live and wings LYGOCORIS PABULINUS
feed on the surface film, but they move The common green capsid bug
in a slow and stealthy way, creeping HYDROMETRA STAGNORUM UMBONIA CRASSICORNIS is a European pest that attacks
up on their prey. They are 1⁄8 – 3⁄4 in Like all water measurers, this European bug Members of this genus are found in woodland fruit and vegetable crops.
(0.3 – 2.2 cm) long, with an elongated is sensitive to surface vibrations and can locate and forests in North and South America and Feeding by this bug leaves
head and bulging eyes. Most species small prey, which it spears with sharp mouthparts. Southeast Asia. The pronotum is tough and raised, warty spots on fruit.
have either short wings or no wings can puncture skin or penetrate shoes.

560 ARTHROPODS

Order Hemiptera continued

Family Notonectidae segmented Family Reduviidae stout front legs
rostrum designed to
Back-swimmers Assassin bugs hold prey
long hindlegs
Occurrence 350 spp. worldwide; in still water, mostly for swimming Occurrence 6,000 spp. worldwide, especially tropical bright
small pools, ponds, edges of lakes NOTONECTA GLAUCA and subtropical regions; on ground, in leaf litter, on markings
Like other back-swimmers, this European plants
These spindle-shaped bugs, species stores air under its wings. It detects its PLATYMERIS BIGUTTATA
1⁄16 – 1⁄2 in (2 – 17 mm) long, are good prey by sight, and by sensing surface ripples. Assassin bugs get their name from their This is a large, highly
fliers, but spend much of their lives predatory habits, although some live predatory Afrotropical species,
underwater, swimming upside down. by sucking blood. Most are 7⁄32 – 11⁄2 in 11∕4 – 11⁄2 in (3 – 3.6 cm) long. Its
They use their forelegs to catch prey (0.7 – 4 cm) long, with dark, slender toxic saliva may cause temporary
and their hindlegs for swimming. bodies. Many attack insect pests; others blindness.
suck blood of humans—transmitting
infection such as Chagas disease.

Family Pentatomidae barrel-shaped eggs, up to 400 at a Family Tingidae
time, on plants. There are 5 nymphal
Stink bugs stages. Nymphs are mostly herbivorous Lace bugs
to begin with but some turn predatory
Occurrence 5,500 spp. worldwide; on herbaceous later, or become mixed feeders. Several Occurrence 2,000 spp. worldwide; on foliage of
plants, shrubs, trees species are serious pests of a wide- herbaceous plants, trees
ranging variety of crops, such as
legumes, potato, cotton, and rice.

Also known as shield bugs because red and black
pronotum
I N V E R T E B R AT E S of their shieldlike shape, these black dorsal Lace bugs are small, grayish insects,
bugs are 3⁄16 – 1 in (0.5 – 2.5 cm) surface of EURYDEMA DOMINULUS recognizable by the complex, lacelike
long. The name stink bugs head The brassica bug has patterns on their wings and upper body.
bold red or orange They are 1⁄16 – 3⁄16 in (2 – 5 mm) long. The
comes from their ability to coloring that serves pronotum can extend, hoodlike, over
to warn predators of its the head. Females of some species take
give off strong defensive odors distastefulness. Found care of the eggs and nymphs. Many are TINGIS CARDUI
across Europe, it is a pests on plants. The spear-thistle lace bug is common in the UK
from their thoracic glands. Many and eats certain types of thistles. A covering of
pest of brassica crops. light, powdery wax gives it a pale gray look.
species are green or brown but

some may be brightly colored. The

pronotum is broad and may have sharp

corners. Females lay clusters of

large, black mark Order Thysanoptera
on scutellum
Thrips
3 pale spots shieldlike
on edge of shape This order consists of 7,400 species within 14 families. Thrips are
large scutellum small and slender, with 2 pairs of narrow, hair-fringed wings. They
have large eyes, short antennae, and sucking mouthparts, with one
small and one needlelike mandible. A sticky, inflatable structure
between the claws aids grip. Metamorphosis is unusual, with
2 nymphal stages and one or more pupalike stages.

sculptured body surface PALOMENA PRASINA Family Thripidae
NEZARA VIRIDULA This is the green shield bug,
The green vegetable bug is abundant in found commonly in woodland and Common thrips
tropical, subtropical, and warm temperate on shrubs across Europe. It is a minor
regions. It is a pest of more than 100 pest of beans and alfalfa crops. Occurrence 2,000 spp. worldwide; in leaf litter, on
plants, mostly vegetables and legumes. leaves, flowers, and fruit of a wide range of plants

Family Psyllidae In warm, humid weather, clouds of THRIPS FUSCIPENNIS
common thrips, or thunderbugs, form This dark-colored species, the rose thrips, with
Jumping plant lice part of the aerial plankton—myriad tiny, distinctive hair on its body, is abundant in the
winged insects that are blown far and Northern Hemisphere, and is found on a wide
Occurrence 1,500 spp. worldwide; on stems, leaves, wide by the breeze. Common thrips range of plant species.
and bark of herbaceous and woody shrubs, trees, crops vary from pale yellow to brown or black, THRIPS SIMPLEX
and have very narrow, feathery wings. The gladiolus thrips was originally from South
Looking like small leafhoppers (see CACOPSYLLA PYRICOLA Typical species are less than 1⁄16 in Africa, but is now also widespread in Europe and
p.558) with long antennae, jumping Abundant in the Northern Hemisphere, the pear (2 mm) long. Some common thrips North America, wherever gladiolus flowers grow.
plant lice are 3⁄64 – 3⁄16 in (1.5 – 5 mm) psylla is a major pest of pear trees, from the reproduce asexually, and in most, the
long, and have 2 pairs of oval wings, leaves of which adults and nymphs suck sap. female inserts eggs into plant tissues or
held rooflike over the body. They flowers using a tiny, sawlike ovipositor.
feed on plants, and some species are The nymphs develop either on plants or
pests. The females lay stalked eggs in the soil. Adults and nymphs generally
on, or in, food plants. live by sucking plant juices, although a
few attack other insects. Some species
are serious pests of tobacco, cotton,
beans, and other crops.

INSECTS 561

Order Megaloptera Order Raphidioptera

Dobsonflies and alderflies Snakeflies

These are the most primitive insects to exhibit metamorphosis. Snakeflies get their name from the snake-like way in which they
Three hundred species in 2 families are weak fliers and never far from catch their prey—raising their head and seizing the prey with a sudden
water. Larvae are aggressive, aquatic predators. They pupate in soil just lunge. There are 2 families and about 200 species. Metamorphosis is
above water level. Once metamophosed, the adults never feed. complete. Larvae hide in bark and litter, and are equally voracious.

Family Corydalidae Family Sialidae Family Raphidiidae

Dobsonflies Alderflies Snakeflies

Occurrence 200 spp. worldwide, especially in Occurrence 100 spp. worldwide, especially in Occurrence 185 spp. primarily in the Northern
temperate regions; in running water temperate regions; in muddy ponds, canals, Hemisphere; among vegetation
slow-moving water

Measuring 1 – 3 in (5 – 7.5 cm) in Alderflies are dark and smoky-winged; Snakeflies are dark, with a distinct
most species are less than 1⁄2 in (1.5 cm) neck formed by a long pronotum.
length, with a wingspan of up to 6 in long. They have long, threadlike Body length varies between 1⁄4 – 11⁄4 in
antennae. Unlike dobsonflies they have (0.6 and 2.8 cm). The head is broad
(15 cm), dobsonflies are large, soft- no ocelli. Females lay egg masses near in the front and tapered at the rear. AGULLA SP.
water, from which hatched larvae drop. Females, slightly larger than males, These snakeflies are found in the woodland of
bodied, gray or brown insects, with 3 These have fully formed legs for crawling, use their long ovipositor to lay eggs the USA and Canada, from the Rocky Mountains
and often mature in a year. in slits in bark. Larvae are elongate to the Pacific coast.
ocelli. Males may have large mandibles, and found under loose bark or
leaf litter. Like the adults, they
used not for feeding but for combat feed on beetle larvae and
soft-bodied insects.
or for holding the female. The latter

lays masses of hundreds of thousands head fixed to small pterostigma
long pronotum on front edge
of eggs near water. large wings with long square of wings, toward
pale marks antennae head the tip

serrated SIALIS SP. transparent netlike I N V E R T E B R AT E S
antennae Common in the Northen Hemisphere, insects of wings pattern of veins
CHAULIODES SP. this genus have typically smoky wings with dark XANTHOSTIGMA XANTHOSTIGMA
Members of this North veins. Fully grown larvae crawl out of water and This species has the order’s characteristic
American genus called fish flies have pupate in damp soil above the water margin. long pronotum, a distinct, broad head that
distinctly rounded corners on their heads. long, slender tapers to the rear, and 4 wings of almost
ovipositor of female equal size. It is found in Europe and Asia.

Order Neuroptera Family Myrmeleontidae weak, fluttering flight. The head is
broader than the pronotum, with large,
Antlions, lacewings, and others Antlions conspicuous eyes. The club-headed
antennae are about as long as the head
This order comprises 14 families and about 11,000 species,
characterized by large eyes, chewing mouthparts, long antennae, Occurrence 2,000 spp. worldwide, in semiarid areas and thorax together. The abdomen in
and 2 pairs of filmy, net-veined wings held over the body when at rest. in subtropical and tropical regions; in woodland, scrub males has terminal sexual clasping
Metamorphosis is complete. The adults are generally predatory and
nocturnal, while the larvae are usually predatory or parasitic. organs that look like earwigs’ forceps.

Eggs are laid in soil or sand, singly or in

small groups. Adults and larvae catch

Family Chrysopidae Family Mantispidae Antlions are soft, large, and slender and eat insects and spiders; some

Common lacewings Mantispids insects that resemble damselflies (see species construct conical pits to trap

Occurrence 2,500 spp. worldwide; in a range of Occurrence 600 spp. worldwide, mainly in warm p.551). The long, narrow wings, which prey. The larvae, sometimes called
microhabitats including vegetation, ant nests temperate to tropical regions; on plants in well-
vegetated areas span 11⁄2 – 43⁄4 in (3.5 – 12 cm), may have doodlebugs, live in these pits with only

brown or black patterns and produce a their spiny mandibles showing, and flick

sand grains at prey to knock them into

the pit. Other larvae live on tree trunks,

in soil and debris, or under stones.

Common lacewings are green or brown, The front legs of mantispids resemble lemon-yellow club-headed
with iridescent wings that span 3⁄8 – 2 in those of praying mantids (see p.554), coloration antennae
(1 – 5 cm) and carry a complex pattern of and are used in the same way. Their
veins. The wings also have ultrasound wingspan is 3⁄8 – 21⁄4 in (1 – 5.5 cm). Eggs black spots
sensors to detect predators such as are laid on tree bark, and the larvae on head
bats. Adults are nocturnal and prey of most species feed on spider eggs.
upon aphids, thrips, and mites. large eyes long, narrow
wings

brown
patterning
on wings

NOTHOCHRYSA CAPITATA CLIMACIELLA SP. TOMATARES CITRINUS slender
Like other lacewings, this European species lays Members of this Central and South American Named after its distinctive lemon- abdomen
eggs on long stalks. The stalks help protect the genus have bright, wasplike, protective coloration. yellow wings, this species is probably
eggs from attack by ants and other predators. distasteful to predators such as birds.
It lives in Africa, like many members
of its genus.

562 ARTHROPODS

Order Coleoptera Family Carabidae long, slender
legs for fast
Beetles Ground beetles running

About one in 3 insects in existence today is a beetle. Collectively Occurrence 29,000 spp. worldwide; on ground, under
they make up an order containing 370,000 known species in 166 stones, logs, in debris, leaf litter, tree foliage
families, and have successfully colonized every sort of habitat on
land and in fresh water. They range in size from insects that are just Measuring 1⁄16 – 31⁄4 in (0.2 – 8 cm) long, CICINDELLA CAMPESTRIS
visible to the naked eye to tropical giants 7 in (18 cm) long. Beetles these elongated and flattened beetles Also known as the green tiger beetle, this
are distinguished by their toughened front wings, or elytra, which can be dull or shiny, brown or black, fast-running, diurnal species can be found
fold over their membranous hindwings like a case. Because the often with a metallic sheen. The head, from April to September on sandy soils in Europe.
hindwings are protected, beetles can squeeze into confined spaces. thorax, and abdomen are clearly
Most species are herbivorous, but the order also includes many differentiated, and the legs are adapted extremely
predators and scavengers, and some parasites. Beetles develop by for quick escape from predators. A few long head
complete metamorphosis: there are distinct larva and pupal stages. species can deter predators using blasts
of hot, caustic chemical substances very long,
Family Anobiidae branched expelled with an audible “pop” from the threadlike
antennae end of their abdomen. Most species are antennae
Woodworm in males nocturnal hunters; adults and larvae
are mostly predatory. Eggs are laid
Occurrence 1,500 spp. worldwide, especially in on the ground, on vegetation, and on
temperate regions; in wood, warehouses, stores, houses decaying wood and fungi.

These small, elongated to oval beetles short legs contrasting striated flat body lets
are pale or reddish brown to black, and markings advertise elytra beetle squeeze
are mostly 1⁄16 – 1⁄4 in (2 – 6 mm) long. The distastefulness under bark
head is often hooded by the pronotum.
I N V E R T E B R AT E S Eggs are laid in suitable food, into body outline
which the larvae bore tunnels. Several resembles a violin
species are pests of cereals, legumes, MORMOLYCE PHYLLODES
spices, and tobacco. The violin beetle is found in the tropical
forests of Southeast Asia, and feeds
PTILINUS PECTINICORNIS THERMOPHILUM SEXMACULATUM on insect larvae and snails.
Found in the UK and central Europe, this species Commonly called the domino beetle, this
is especially associated with beech trees and Afrotropical species hunts during the day
may attack wood furniture. in semiarid areas.

Family Buprestidae Family Cerambycidae Family Chrysomelidae

Jewel beetles Longhorn beetles Leaf beetles

Occurrence 15,000 spp. worldwide, primarily in tropical Occurrence 30,000 spp. worldwide; on flowers, bright Occurrence 35,000 spp. worldwide; widespread
regions; in sunny glades, on bark or flowers at sap flows coloration on most types of plants

Most jewel beetles are a brilliant, Also known as timber beetles, PHOSPHORUS JANSONI Although some eat pollen, adults in this
metallic green, red, or blue, with spots, these insects are serious pests of This species is a native family are mostly leaf eaters—hence the
stripes, and bands. They are 1⁄16 – 21⁄2 in wood. Their larvae, responsible for of African forests. It lays name. This makes many species serious
(0.2 – 6.5 cm) in length and taper toward the damage, tunnel through living its eggs in trees, and its
the rear. They lay eggs in wood—some trees, and also through wood in larvae attack economically pests, although a few have been
species have heat sensors that can buildings. Once adult, they feed important species such used in biological control of
detect freshly burned areas where they on sap, pollen, nectar, or leaves. as the cola tree. weeds. Leaf beetles range from
may mate and lay eggs—and the larvae Adult beetles have strong, toothed cylindrical and elongated, to
are typically wood feeders. Many mandibles, parallel-sided bodies, strong, toothed eyes notched round-backed. They measure 3⁄8 – 11⁄4 in
and are 1⁄8 – 6in (0.3 – 15 cm) long. They mandibles where antennae (1 – 3 cm) in length, with the antennae
species are lumber pests. Adult are often brightly colored, but their arise less than half the body length. Many
beetles feed on nectar, flowers, most striking feature is their antennae, species are brightly colored. Eggs are
and pollen. Their bright wing which may be up to 4 times as long laid in groups on host plants or in soil.
cases are used in as the body. Females lay their eggs
headdresses or singly under bark. Like many wood- robust
as ornaments. boring species, the life antennae
cycle can take several
years to complete. squarish pronotum

irregular STERNOTOMIS BOHEMANNI parallel- SAGRA BUQUETI curved
dark spots This Afrotropical species sided Found in Africa and tibiae
on elytra has the typical longhorn body Asia, the jeweled frog
CHRYSOCHROA BUQUETI shape. The females use beetles are named for
This beetle is found in tropical forests of their mandibles to cut XIXUTHRUS HEROS their strong hindlegs,
Vietnam and Thailand and is highly prized through bark, under This large longhorn beetle is 31⁄4 – 4 in used in male-to-
by collectors. In places, this has led to a which they lay eggs. (8 – 10 cm) long and is endemic to Fiji. male combat.
decline in local populations. The males are territorial.

INSECTS 563

Family Coccinellidae Family Curculionidae elbowed Family Dermestidae
antennae
Ladybugs Weevils Larder beetles
cryptic
Occurrence 5,000 spp. worldwide; almost anywhere on Occurrence 50 – 55,000 spp. worldwide; associated with markings Occurrence 950 spp. worldwide; mostly associated
foliage where insect prey is present almost every terrestrial and some aquatic plant species CRATOSOMUS with dried animal remains
RODDAMI
Habitat Terrestrial The larvae of this
South American
Also called lady beetles or ladybirds, Weevils, also known as snout beetles, weevil bore into Many species of larder beetles are
these short-legged beetles are brightly form one of the largest families in the the stems of their
colored, often with spots or stripes. animal kingdom. Most have a rostrum, host plants. serious pests of food or animal matter
They are 1⁄32 – 1⁄2 in (1 – 15 mm) long, which is an extension of the head and
rounded and convex, with the pronotum carries the mouthparts. The body is long, thin stored in buildings; larvae scavenge
often hiding the head. They are either 1⁄32 – 31⁄2 in (0.1 – 9 cm) long, and may rostrum
shiny and smooth, or hairy. Antennae be cryptically or brightly colored, on dried meat or fish, and on plant
are segmented, with a short, terminal with patterns and metallic scales.
club. Eggs are glued singly or in small The antennae are usually 11-segmented, material, woollens, silks, or furs. These
groups to plants. Although some and are elbowed or bent. Eggs are laid
species are herbivorous, most adults inside plant tissue or in soil. Mostly beetles are either rounded or slightly
and larvae are predators of soft-bodied diurnal, adults chew and eat soft plants,
insects. This makes them useful as while larvae mostly feed inside plant elongated, and measure 1⁄16 – 3⁄8 in
controlling agents of pests. tissue. Many weevils are crop pests.
(2 – 12 mm) in length. Dull brown or

black, they are usually covered with

patterns of colored hairs or scales.

hairy Females lay up to 150 eggs, pronotum
front in about 2 weeks, on hides head
tibiae foodstuffs. The hairy

larvae feed at a great

rate and, in hot

hindwings variable blue countries, mature
extended only markings
in flight oval dark in a few weeks.
body coloring
The adults feed on

pollen and nectar.

expanded These beetles are
tarsal
bright colors segments also called skin or I N V E R T E B R AT E S
deter predators EUPHOLUS BENNETTI
ANATIS OCELLATA This brightly patterned museum beetles.
Also known as the eyed insect is found in Southeast
ladybird, this unmistakable large Asia and Papua New Guinea. CYRTOTRACHELUS SP. DERMESTES LARDARIUS
European species feeds on jumping The males of this Southeast Found worldwide, this species inhabits bird nests,
plant lice and other small prey. Asian genus have long, hairy front warehouses, dry corpses, and animal matter. It
tibiae, used in courtship displays. feeds on dried meat and cheese in houses.

Family Dytiscidae hairy hindlegs Family Histeridae Family Lampyridae
adapted for
Predacious diving propulsion Hister beetles Fireflies
beetles
Occurrence 3,000 spp. worldwide; in dung, carrion, Occurrence 2,000 spp. worldwide; on vegetation in
Occurrence 3,500 spp. worldwide; in streams, shallow under bark, in tunnels of wood-boring insects, ant nests woodland and moist grassland, in soil, under stones
lakes and ponds, brackish pools, thermal springs

These beetles are 1⁄16 – 2 in (0.2 – 5 cm) smooth, These tough-bodied beetles have a Also known as lightning-bugs, many
long, oval, and mostly black or dark shiny body rounded or oval outline; some species fireflies use species-specific flashes
brown. They are fierce predators that may be flattened. Most species are of cold green light made by luminous
attack everything from other insects suction pads on black or metallic, and have striations organs on their abdomen in order to
to mollusks or vertebrates. Larvae are front legs of males on the elytra and other body parts. attract mates. The females of some
called water tigers. Well adapted to They are mostly less than 1⁄2 in (1.5 cm) species even imitate the flashing of
aquatic life, the adults can carry air DYTISCUS MARGINALIS in length. Eggs are laid in foodstuffs. closely related species to lure males
supplies beneath their wing cases. The great diving beetle inhabits ponds and Adults and larvae are predatory and and eat them. Fireflies are 3⁄16 – 11⁄4 in
shallow lakes in Europe and Asia. The male feed on fly and beetle larvae, and mites. (0.5 – 3 cm) long. Males are usually fully
Family Elateridae has suction pads on its front legs for holding winged, whereas some females are
onto the female during mating. large, curved wingless and may resemble larvae.
Click beetles mandibles The larvae eat a small range of snails
elongated to oval, and parallel-sided, small clubs and other invertebrates. Most adults
Occurrence 9,000 spp. worldwide; around plants, in tapering at the rear. Body length ranges at end of feed on nectar or dew, although
leaf litter, rotten wood, soil from 1⁄16 – 23⁄4 in (0.2 to 7 cm). Eggs are antennae some are predatory.
laid in soil and plant matter. The larvae,
Click beetles, also called skip jacks, called wireworms, are generally elytra do branched
are able to propel themselves into the not cover antennae
air, making a loud “click” that frightens predatory, although some feed on abdomen
predators. Their rapid jump is made plant roots and tubers. head hidden
possible by powerful thoracic muscles expanded by large
and a unique “peg-and-joint” catch lateral tibiae, with pronotum
mechanism on the underside of markings short teeth,
the thorax. They are dull in color, on elytra aid digging orange and black-
brown coloration
deters predators

CHALCOLEPIDIUS LIMBATUS HOLOLEPTA SP. LAMPROCERA SELAS
Found in South America, this species eats Commonly called flat hister beetles, the species This firefly inhabits moist
plants as well as insects. Larvae develop in this genus have a very flat and hard body grassland and semiwoodland
in soil, litter, or rotting wood. surface. They live under the bark of fallen trees. in tropical South America.

564 ARTHROPODS

Order Coleoptera continued

Family Lucanidae head smaller Family Passalidae comblike, strong, spiny
than pronotum segmented tibiae
Stag beetles Bess beetles antennae
spined fringe
front legs Occurrence 500 spp. in tropical regions, mainly striations of hairs
woodland of South America and Asia; in dead wood on elytra
Occurrence 1,300 spp. worldwide, in deciduous PHALACROGNATHUS
woodland and forests; in and on trees

MULLERI
The king stag beetle
has a distinctively
colored, metallic
Stag beetles are smooth, black or body. It is found in Also called patent-leather or betsy
reddish brown, and mostly 1⁄4 – 31⁄4 in the rain forests of beetles, these insects are shiny black or
brown, with a flat body that is 3⁄8 – 31⁄4 in
(0.6 – 8.5 cm) long. Males are larger than northern Australia. shiny, (1 – 8.5 cm) long. The elytra have
metallic noticeable striations, and the head often
females and have enlarged mandibles elytra has a short horn. Adults make high- shiny black
elbowed pitched sounds in aggression or during color
used in male-to-male combat over bent antennae courtship. Eggs are laid in dead wood. ACERAIUS RECTIDENS
females. Eggs are laid on decaying mandibles Found in the woodland of Southeast Asia, this

tree stumps or roots, and larvae pupate beetle has curled, 10-segmented antennae, and

inside a cell of chewed wood fibers. a short peg on the head.

Adults are nocturnal and large shovel-shaped
either do not feed, or take head head
red metallic sheen
fluids such as nectar. Family Scarabaeidae
KHEPER
mandibles grasp Scarab beetles AEGYPTIORUM
rival’s body This is the large,
Occurrence 16,500 spp. worldwide; on dung, carrion, colorful sacred
MESOTOPUS large, shiny fungi, vegetation, under bark, in ant or termite nests scarab of Africa,
black body probably the first
TARANDUS Members of this family are extremely to be revered in
I N V E R T E B R AT E S Found in the forests varied in shape, size, and color; Ancient Egypt. It
of Africa, this species has large, toothed subfamilies include dung beetles, rolls dung into large balls, which
mandibles, bent almost at right angles. Hercules beetles, and leaf chafers. it buries and in which it lays eggs.
The body length ranges from 1⁄16 – 61⁄2 in
LUCANUS CERVUS (0.2 – 17 cm). The ends of the antennae shiny golden elytra
This stag beetle is found in the oak woodland have a distinct club made up of 3 – 7 flat,
of Europe. It flies after dark. The species is movable plates. Males of many species strong
becoming more rare due to loss of habitat. have an enlarged head or horns to fight claws
over mates. Eggs are laid—and larvae
Family Silphidae Family Staphylinidae can be found—in soil, rotten wood,
or dung (which dung beetles roll
Carrion beetles Rove beetles into a ball and bury).

Occurrence 250 spp. worldwide, mainly in Northern Occurrence 29,000 spp. worldwide; on ground, in soil, stout hind
Hemisphere; on ground near carcasses, dung, and fungi fungi, leaf litter, decaying plants, carrion, ant colonies femora
CHRYSINA RESPLENDENS
Sometimes called precious metal scarabs due
to their gold or silver coloring, this rare scarab
and its relatives are found in South America.

Carrion beetles are usually flat and Most rove beetles are small—usually POLYPHYLLA STARKAE
soft-bodied, 5⁄32 – 13⁄4 in (0.4 – 4.5 cm) This beetle belongs to a genus of scarab beetles
long. They are black or brown, often under 3⁄4 in (2 cm) in length—smooth, that occur across the Northern Hemisphere. They
with bright yellow or red markings. have their greatest diversity in southern USA.
In carcass-burying species, such as and elongated. They are often brown Described in 2009, this species was discovered
Nicrophorus (burying beetles), the on the Florida peninsula.
elytra are shortened, exposing a few or black, although some have bright
abdominal segments. These beetles
bury corpses of small animals and lay colors and a sculptured body surface.
eggs on them. Adults often feed larvae
on regurgitated carrion. They all have short elytra, with

clubbed hindwings folded beneath them, and
antennae
an exposed abdomen. The smaller
flat, broad
body species tend to be flexible, exposed Family Tenebrionidae
diurnal, while abdomen
coarse bumps the larger ones Darkling beetles
on elytra pronotum
are nocturnal. flat head and Occurrence 17,000 spp. worldwide; on ground in all rounded
SILPHA Eggs are laid prothorax terrestrial habitats, especially in desert and arid regions at sides
AMERICANA
Like all members of its family, this beetle is in soil, fungi,
attracted by the odor of carrion. It is found
in North America and has a distinctive broad or leaf litter.
shape with fairly bright coloration.
matt black Darkling beetles vary considerably in smooth,
body color (black or brown body, or white rounded
STAPHYLINUS OLENS elytra), shape (parallel-sided or large body
Known as the devil’s coach horse, this is a large, and oval), and texture (smooth and
black European species, 3⁄4 – 11⁄2 in (2 – 3.4 cm) shiny or dull and rough). They are strong
long. If threatened, it assumes a scorpionlike 1⁄16 – 2 in (0.2 – 5 cm) long. Many species legs
posture by curving its abdomen upward. have reduced hindwings and do not fly.
These beetles eat decaying vegetable pointed
or animal matter, and some are pests elytra
of stored products. A few secrete a
foul chemical repellant. BLAPS MUCRONATA
The cellar, or churchyard, beetle is a nonflying,
European species that favors dark places.

INSECTS 565

Order Strepsiptera Order Siphonaptera

Strepsipterans Fleas

With their small size, parasitic lifestyle, and extreme sex differences, Fleas are brown, shiny, wingless insects, superbly adapted for
strepsipterans make up one of the most unusual orders of insects. a parasitic lifestyle feeding on mammalian blood. Their bodies are
Males usually have wings, the hindwings often being twisted, but flattened sideways, which helps them to slip through fur, and they
females are grublike, and spend their lives lodged in the bodies of are very tough, which makes them hard to kill. They leap onto suitable
larger insects, such as bugs, bees, or wasps. There are about 580 host animals using their enlarged hindlegs, which store energy in
species, in 8 families, and all undergo complete metamorphosis. special pads of rubberlike protein. There are over 2,500 species
(18 families) of fleas; all undergo complete metamorphosis. Larvae
Family Stylopidae host. They may cling to the host’s body scavenge on debris, dried blood, and adult flea excrement.
or be ingested with nectar. In many
Stylopids cases, once inside the host’s nest, Family Pulicidae attracted by its body heat. However,
they leave the body or are regurgitated if they fail to find a host, or become
Occurrence 268 spp. worldwide; in vegetated habitats and proceed to parasitize the eggs or Common fleas dislodged, they can survive for a long
where hosts are found, females in bees and wasps larvae. The sexual organs of the time without food. Many species of
parasitized host also degenerate. Occurrence 200 spp. worldwide; on mammalian hosts, common fleas, such as the cat flea, dog
Male stylopids are small and in lairs, burrows flea, and human flea, are of medical
dark, with bulging eyes and conspicuous hindwings twisted importance. Their bite causes severe
bodies that are 1⁄64 – 5⁄32 in eyes in appearance Common fleas parasitize humans and a itching and allergic reactions, as well as
(0.5 – 4 mm) long. Like all wide range of other mammals, including spreads diseases and parasitic worms.
strepsipterans, their forewings dogs, cats, and other carnivores, as The bacterium that caused bubonic
are tiny and their hindwings well as hedgehogs, rabbits, hares, and plague in medieval Europe was carried
relatively large and fanlike. rodents. Some of them have a broad by various types of rat flea.
Females have neither legs nor host range, occurring on up to 30
wings, and never leave the body different animal species. Common fleas backward-
of the host insect. After mating, are 1⁄32 – 5⁄16 in (1 – 8 mm) long and often pointing
thousands of eggs hatch inside have combs of backward-pointing bristles
the female; some species may lay bristles on their cheeks—features that
up to 70,000 eggs. The active, tiny, STYLOPS SP. are an important aid in species enlarged I N V E R T E B R AT E S
6-legged larvae (triungulin) leave the Males of these species have a highly identification. Adult females lay eggs hindlegs
female through a special passage and distinctive shape, with branched antennae as they feed, dropping them into their for jumping
crawl onto flowers to wait for the next and the order’s characteristic berrylike eyes. hosts’ nests, burrows, or bedding,
where they hatch to produce pale,
Order Mecoptera wormlike larvae that have tiny, biting SPILOPSYLLUS
jaws. The larvae typically live for 2 – 3 CUNICULI
Scorpionflies weeks, before pupating in a minute silk Commonly known as
cocoon. Once they have become adult, the rabbit flea, this species
The males of some species in this order have a scorpionlike, slender the fleas remain inside their cocoons is widespread in the Northern
abdomen—hence the common name. Metamorphosis is complete. for weeks or months until they sense Hemisphere. It carries the
There are 9 families and 550 species of scorpionflies. vibrations from a nearby animal. They rabbit disease myxomatosis.
then emerge from their cocoons and
jump aboard their prospective host,

Family Bittacidae spine at end
of tibiae
Hangingflies
slender, long eyes touch spiny PULEX IRRITANS
Occurrence 170 spp. in the Southern Hemisphere; in brownish abdomen cheek combs hindlegs This species was once the most common
damp, wooded or well-vegetated, shady areas wing hind tarsi CEDISPSYLLA SIMPLEX flea attacking humans; today, cat and dog
can fold This species is found on cottontail fleas are more dominant. It also attacks pigs,
Hangingflies use their front legs to HARPOBITTACUS around prey rabbits in North America. goats, and badgers, and can be a carrier of
hang from vegetation and hindlegs AUSTRALIS bubonic plague.
to catch prey. The adults are 1⁄2 – 11⁄2 in This is an Australian species
(1.5 – 4 cm) long. Eggs are laid in soil. with brownish wings and
orange-red banded legs.

Family Panorpidae slender
antennae
Common
scorpionflies

Occurrence 360 spp. mostly in the Northern
Hemisphere; among vegetation in woodland and scrub

brown wings
with white patches

These insects are ⁄11 32 – 1 in (0.9 – 2.5 cm) PANORPA upturned, CTENOCEPHALIDES CANIS CTENOCEPHALIDES FELIS
long, often with mottled wings. Adults eat LUGUBRIS swollen Very common in human habitations the world The cat flea is a common domestic species found
nectar, fruit, and insects. They lay eggs in This species is common in genitalia in over, the dog flea is reddish brown, with a head in temperate regions. A cat may have only a few
soil, where hatched larvae pupate. parts of North America. Males males that is more domed than that of the cat flea. It adult fleas feeding on it but its bed supports
are larger than the females. is a carrier of the dog tapeworm, which can thousands of larvae. Hungry cat fleas can jump
also affect cats and humans. up to 131⁄2 in (34 cm) and readily bite humans.

566 ARTHROPODS

Order Diptera Family Asilidae Family Bombyliidae

Flies Robber flies Bee flies

Flies have only a single pair of wings (although some ectoparasitic Occurrence 5,000 spp. worldwide, especially in tropical Occurrence 5,000 spp. worldwide, in open, tropical,
species are wingless). The hindwings are reduced to small, club- and subtropical regions; in a variety of microhabitats or subtropical semiarid regions; around flowers,
shaped balancing organs called halteres. Flies are ecologically on ground
essential as pollinators, parasites, predators, and decomposers, but
many damage crops, and the disease-carrying species have a huge This is a family of predatory flies; both the Bee flies are stout and hairy insects
impact on wild and domesticated animals, as well as on humans. adults and larvae are predatory, although
the latter eat decaying matter as well. that strongly resemble bumble bees (see
There are 130 families and 150,000 species of flies, divided into Robber flies use their forward-pointed,
2 suborders, Nematocera (26 families) and Brachycera (104 stout and sharp proboscis to stab prey p.573). Between 1⁄16 – 11⁄4 in (0.2 and 3 cm)
families). The former are delicate, with threadlike antennae and inject a paralyzing saliva. They
and slender bodies, while the latter are more robust, with stout then suck up the body contents of long, they are brown, red, or yellow,
antennae. All have complete metamorphosis: larvae (“maggots”) the paralysed insect. They are 1⁄8 – 2 in
may have a reduced head. Larval feeding habits are among the (0.3 – 5cm) long, either slender or stout sometimes with bright markings. They
most diverse in insects. and beelike. Their head is slightly hollow
between the eyes, and the face has have narrow wings, and when flying
a tuft of long hairs. Eggs are laid in
soil, rotting wood, or inside plants. produce a high-pitched whine. Like bees,

sharp proboscis they have a long proboscis that they use

to suck nectar from flowers. However,

Family Agromyzidae instead of landing on flowers as bees do,

Leaf-mining flies bee flies hover in front of them, steadying

Occurrence 2,500 spp. worldwide; on leaves, stems, themselves against the petals with their
seeds, roots of a wide range of plants, including crops
front legs. Some bee fly larvae

eat grasshopper eggs, but long
most are parasitic proboscis

and attack beetles,

Habitat Terrestrial moths, wasps,

This family gets its name from the ability or other flies.
of larvae to chew mines (channels) in
I N V E R T E B R AT E S leaves. These crop pests also feed broad
inside stems, seeds, or roots. Gray, wingspan
black, or greenish yellow, they vary
from 1⁄32 to 1⁄4 in (1 – 6 mm) in length. smoky tint stout, hairy
Females have a pointed ovipositor, on wings body
and lay up to 50 eggs a day inside HEXOMYZA SP.
plant tissue. These flies may live for These species occur throughout the Northern stout, bristly legs BOMBYLIUS MAJOR
as little as 2 weeks in tropical areas. Hemisphere, and in South Africa and Australia. BLEPHAROTES SPLENDIDISSIMUS The large bee fly is common and inhabits
The larvae make galls on the twigs of poplars. This large Australian robber fly has platelike tufts meadows, hedgerows, and open areas
of hair at the sides of its flat abdomen. from Europe to China, and North Africa.

Family Calliphoridae Family Cecidomyiidae food. Like gall wasps (see p.574),
gall midges are species-specific,
Blow flies Gall midges always attacking particular
kinds of plants. Adult gall
Occurrence 1,200 spp. worldwide; on flowers, Occurrence 5,000 spp. worldwide; anywhere near midges have long, slender
vegetation, carcasses, cooked and raw food decaying matter, fungi, a wide range of plants legs, and wings with a
few unbranched veins.
Bluebottles and greenbottles are POLLENIA RUDIS With bodies typically less than 5⁄32 in A number are
familiar members of this widepread and Common in the Northern Hemisphere, cluster (4 mm), gall midges are seldom seen, serious pests
sometimes troublesome family of flies. flies congregate in large numbers in attics but their larval homes—plant galls— of crop plants.
Like their many relatives, they have stout, and unheated buildings. In the spring, adult are much easier to spot. Looking like
bristle-covered bodies, up to 1⁄2 in (1.5 cm) females lay their eggs on earthworms or miniature fruit or malformed buds, the threadlike
long, a metallic sheen, particularly on near fresh worm casts. galls are growths triggered by some gall antennae
the abdomen, and a noisy, buzzing midges, for protection and as a source of
flight. Blow flies breed in decaying animal ASPHONDYLIA SPP. very long,
matter, dung, or rotten fishes. Adults feed Family Ceratopogonidae Each species in this genus thin legs
on liquids from rotting material, nectar, makes a characteristic gall.
or fruit. The larvae of some species are Biting midges
predators of ants, termites, and the black, bristly thorax
larvae and eggs of other insects. Several Occurrence 4,000 spp. worldwide, mainly in the
species burrow into human flesh and spongelike metallic- Northern Hemisphere; near margins of water bodies Some biting midges transmit worm
many carry diseases that they can mouthparts blue parasites to humans or carry animal
transmit to livestock or humans. for lapping abdomen Habitat All diseases. They are pests but are also
up fluids important pollinators of tropical crops
Also called punkies or no-see-ums, such as cocoa or rubber.
these small flies—under 3⁄16 in (5 mm)
metallic- stout bristles CALLIPHORA VOMITORIA long—have a bite that causes severe
blue body The bluebottle fly is common in the countryside irritation. They have short, strong legs,
in the Northern Hemisphere. Females may dark patterns on their wings, and
lay many hundreds of eggs in their lifetime. piercing mouthparts shaped to suck
blood and insect body fluids. They mate
minute CALLIPHORA VICINA while flying in a swarm. Eggs are laid in CULICOIDES IMPUNCTATUS
claws This widespread species is groups of 30 – 450, and are covered This notorious European species breeds in
common in towns and cities, with a protective, jellylike substance. boggy areas. The bite of the female common
where the maggots develop midge is extremely itchy and painful.
inside the corpses of dead
rats, mice, and pigeons.

INSECTS 567

Family Chironomidae sticky jelly on water or plants. The larvae Family Drosophilidae Family Empidae
are plentiful in freshwater; up to 100,000
Non-biting midges larvae have been recorded in 11 square Pomace flies Dance flies
ft (1 square meter).
Occurrence 5,000 spp. worldwide; near ponds, lakes, Occurrence 2,900 spp. worldwide; near decaying Occurrence 3,000 spp. worldwide, mainly in the
and streams; swarms occur at dusk long legs male has vegetation, fruit, fungi, fermenting liquids Northern Hemisphere; adults on tree trunks, larvae
with fine hairs feathery in rotten wood
These delicate, pale brown or greenish antennae Habitat All
flies resemble mosquitoes, but do not The common name of this family comes
have functional mouthparts. They are slender CHIRONOMUS RIPARIUS Also known as lesser fruit flies or vinegar from the dancing motions of mating
1⁄32 – 1⁄32 in (1 – 9 mm) long. The males have body of This is a common, flies, these small, yellow, brown to swarms. Dance flies are 3⁄64 – 1⁄2 in
a slender body and feathery antennae, male European species whose reddish brown, or black species have (1.5 – 15 mm) long. Most species have a
while the females are stout, with hairy larvae live in stagnant water. light or bright red eyes. The thorax and stout thorax, an elongated abdomen,
antennae. Most of the 2 – 3-year life cycle the abdomen may be striped or spotted. a rounded head with large eyes, and a
is spent as larvae; adults live no longer but females feed on blood—chiefly Pomace flies are 1⁄32 – 1⁄4 in (1 – 6 mm) long. downward-pointing, sharp proboscis
than 2 weeks. They mate on the wing in from mammals and birds—and have Males make a buzzing sound with their with which they can stab prey. Courtship
a swarm, and lay their eggs in a mass of syringelike mouthparts for piercing skin. wings to attract mates. Eggs are laid
They lay their eggs on stagnant water. near a food source at the rate of 15 – 25 often involves males offering prey as
Family Culicidae food to females. Eggs are laid
humped long proboscis eggs per day. Larvae feed on on soil, dung, or plant matter.
Mosquitoes thorax bacteria and fungi, while While adults eat small flies
the adults look for and drink nectar, larvae
Occurrence 3,500 spp. worldwide, especially in broad abdomen fermenting liquids and feed on soft- I N V E R T E B R AT E S
warmer regions; everywhere near water CULEX SPP. rotting fruit. bodied prey.
These mosquitoes rest with pale halteres
Habitat All their bodies parallel to the translucent
surface; the malaria-carrying wings piercing
Mosquitoes are among the world’s most Anopheles species rest in proboscis
dangerous pests, spreading malaria, a head-down position. brownish
yellow fever, and several other potentially coloration long,
fatal diseases. They are 1⁄8 – 3⁄4 in bristly legs
(0.3 – 2cm) long, with narrow bodies, DROSOPHILA MELANOGASTER
a humped thorax, and slender legs. The best-known pomace fly, the laboratory EMPIS SP.
Males often feed on flowers, fruit fly is often used for genetics studies, as These flies inhabit damp vegetation. The
it breeds quickly and has large chromosomes long proboscis enables the fly to “stab” its
in its salivary glands. prey and extract fluids on which it feeds.

Family Hippoboscidae Family Muscidae yellowish Family Keroplatidae
base to
Louse flies Muscids wings Fungus gnats

Occurrence 200 spp. worldwide, mainly in tropical and Occurrence 4,000 spp. worldwide; on flowers, Occurrence 1,000 spp. worldwide; in forests, caves,
subtropical regions; ectoparasites of birds and mammals dung, decaying matter, near mammalian hosts and other moist places

Habitat Terrestrial

These dull brown, stout, flat, and hairy The muscid family includes one of the yellow fine Usually found in association with fungi in
flies, mostly 5⁄32 – 9⁄32 in (4 – 7 mm) long, world’s most successful insects— femora bristles dark, damp forest habitats, keroplatid
have a short proboscis and strong, the common house fly—together with fungus gnats also occasionally live in
clawed legs for gripping hairs or feathers. its many relatives. Muscids are usually MYDAEA CORNI caves. Adult keroplatids generally have
Some have fully formed wings, but in drably colored, with bristly bodies up This species, found in Europe and Asia, dark bodies and may have patterned
others the wings are vestigial, or absent to 3⁄8 in (1.2 cm) long, and mouthparts inhabits dung. The larvae are predators on wings; one group mimic wasps. The larvae
altogether. Females lay mature larvae that are spongelike for lapping fluids, small organisms inside the dung. of some feed on fungi, but others are
(prepupae) one at a time; these develop or piercing for sucking blood. Female predators, ensnaring other insects and
inside a “uterus,” feeding on secretions houseflies can lay 100 – 150 eggs per slender worms in slimy threads and killing them
from special “milk” glands. Adult louse day in rotting matter, dung, fungi, legs with oxalic acid produced by mouth
flies are blood-suckers. water, or plants. Maggots grow fast glands. Several species, including the New
and, in ideal conditions, pupate in MUSCA DOMESTICA Zealand cave “glowworm” (Arachnocampa
head partly just over a week. These flies can carry The common house fly is
sunk into infections such as typhoid and cholera. found throughout the world, luminosa), have luminescent
thorax and spreads bacterial and larvae to attract prey.
viral diseases.

orange patches on
sides of abdomen

smoky wings large eyes long,
HELINA OBSCURATA translucent slender
This species is widespread wings antennae
in the Northern Hemisphere.
vestigial black The larvae are predatory on MACROCERA STIGMA elongated
wings femora small organisms found in This is a widespread, first leg
CRATAERINA PALLIDA soil and humus. west European species segments
Also called the swift louse fly, this European slender legs that inhabits damp,
species is parasitic on swifts in their nests. Three- shady places. It has
quarters of all louse fly species parasitize birds. hairs on its wings.

568 ARTHROPODS

Order Diptera continued Family Phoridae Family Psychodidae fluttery or hopping flight pattern. Female
sand flies are blood-suckers and,
Family Oestridae Scuttle flies Sand flies and particularly in the tropics, several
moth flies species spread diseases.
Bot flies and Occurrence 3,000 spp. worldwide; in a wide variety
warble flies of microhabitats Occurrence 1,000 spp. worldwide, especially in very hairy
warmer regions; in water, rotting matter, and moist, thorax
Occurrence 70 spp. worldwide, especially in the Habitat All shady habitats
Northern Hemisphere and Africa; near mammalian hosts broad wings
Also known as hump-backed flies, the These flies measure 3⁄64 – 3⁄16 in
Many members of this heavy-bodied brown, black, or yellowish scuttle flies (1.5 – 5 mm) in length. Their bodies, long hairs on
family look like bees. They are about have characteristically fast, jerky wings, and legs are covered with long wing margins
5⁄16 – 1 in (0.8 – 2.5 cm) long. Because the movements while running. They are hairs or scales. The broad wings are
adults are short-lived and do not feed, 1⁄64 – 1⁄4 in (0.5 – 6 mm) long with a strongly held tentlike or partly spread in moth PERICOMA FULIGINOSA
the mouthparts are either tiny or absent. down-turned head. The antennae flies, or together above the body in sand The larvae of this dark, widely distributed
The larvae are all intestinal parasites of appear to have only one segment and flies. Sand and moth flies have a weak, moth fly are, like sand flies, saprophagous. They
mammals, especially horses, goats, and the hind femora are usually very stout. develop in shallow water and in rot holes in trees.
camels. The females of some species Conspicuous bristles are often present Family Sarcophagidae
lay larvae directly in the nostrils of hosts, on the body; these look feathery when The larvae of many species feed on
where they feed and grow in the sinuses. highly magnified. Adults live from a few Flesh flies carrion, and some are parasitic on other
In warble flies, eggs are laid on the hair days to a week, and may take fluids. insects, spiders, snails, and worms.
Some of the larvae feed on Occurrence 2,300 spp. worldwide, especially in the
of the host, and the larvae burrow fungi or decaying matter; Northern Hemisphere; foliage, flowers, carrion stout bristles
under the skin. Fully grown others feed on insects,
larvae are sneezed out snails, and worms. Some of these robust-looking flies lay pale
by the host or chew larvae in body cavities or wounds in markings
their way out strongly vertebrates, including humans. They
I N V E R T E B R AT E S and pupate developed are mostly dull or silvery gray or black, dark male
in the soil. thorax and are 1⁄16 – 3⁄4 in (0.2 – 2 cm) long. The hairs genitalia
thorax typically has 3 dark longitudinal SARCOPHAGA MELANURA
hairy body downward- strong stripes on a gray background, and This species is common
pointing head femora the abdomen appears checkered or near coastal areas in western
small antennae spotted. Most females give birth to Europe. Its larvae are found
in grooves ANEVRINA larvae that are laid or dropped in flight. in rotting meat and may
on head THORACICA parasitize snails or insects.
HYPODERMA BOVIS Distributed over the
The ox warble fly or northern cattle Northern Hemisphere, the
grub is common in the Northern Hemisphere, larvae of this fly favor soil,
particularly near cattle. It damages hides, the corpses of animals,
and reduces animal vigor and milk production. and moles’ nests.

Family Simuliidae Family Syrphidae them. Hover fly larvae are very varied, The larvae of one group, known

Black flies Hover flies and live on a range of different foods. as drone flies (Eristalis spp.), live in

Occurrence 1,600 spp. worldwide; larvae in flowing Occurrence 6,000 spp. worldwide; common on flowers, Some are predators, attacking aphids, stagnant water, and use a telescopic,
water, adults on plants near water especially umbelliferous ones
sawfly larvae, and other soft-bodied posterior “snorkel” to breathe.
Black flies, also called buffalo gnats Hover flies include some of the
or turkey gnats, are 1⁄32 – 3⁄16 in (1 – 5 mm) most skilled fliers in the insect world. insects, while others feed on rotting
long, and usually black, orange-red, They feed on pollen and nectar, and
or dark brown. Males drink nectar and can often be seen hovering over vegetation or animal dung. A few live SERICOMYIA SILENTIS
water, while females feed on vertebrate flowers, or darting after each other in as scavengers in the nests of bees The common bog hoverfly is found
blood. They lay their eggs on rocks a high-speed chase. Ranging from and wasps, where they eat the dead on acid heathland in Europe. The
or vegetation near water. The aquatic 3⁄8 – 3⁄4 in (1 – 2 cm) in length, they have larvae and pupae of their hosts. larvae live in boggy pools, such as
larvae, attached to submerged rocks large eyes and slender wings, and are
or plants by a hooklike holdfast, filter often colored yellow or orange and SYRPHUS RIBESII short antennae those formed after cutting peat,
food from the water with special bristles black. This coloration—combined with Common in Europe, this and feed in the decaying
around the mouth. their overall shape—makes them look wasplike species often rhizomes of reedmace.
very much like stinging bees or
wasps, and deters many gathers in large numbers,
predators from attacking in flower-rich meadows. eyes in males
Its larvae eat greenflies. usually meet on
top of head

wasplike
shape and
coloring

eyes in females
well separated

SIMULIUM SP. VOLUCELLA ZONARIA false wings with
Although known as black flies, some members This migratory species margin false veins
of this genus are not entirely black. Many species is distributed mainly distinctive, broad,
are carriers of the roundworm that causes river over Europe. It is yellow bands broad wedges
blindness in Africa and tropical America. stout and distinctively of yellow at
banded. Its larvae sides of abdomen
scavenge inside
wasps’ nests.

INSECTS 569

Family Tabanidae mass of 200 – 1,000 on debris Family Tachinidae but their larvae are endoparasites of
overhanging water, leaves, or rocks. insects. Some species locate crickets
Horse flies Larvae are predatory or saprophagous. Parasitic flies to parasitize by listening for their mating
songs. Males and females often
Occurrence 4,000 spp. worldwide, near mammals; stout, dark body Occurrence 8,000 spp. worldwide; where insect congregate on hilltops for mating, and
many favor damp or wet habitats hosts are found the eggs are laid on foliage eaten
large eyes by hosts, or inside the hosts’ bodies.
occupy most Stout and robust, parasitic flies are Parasitic flies are mostly diurnal. Many
of head 3⁄16–3⁄4 in (0.5 – 2 cm) long, and are very species are used as biological control
variable in appearance. Most are dark; agents of herbivorous insect pests.
Horse flies are stout and hairless with TABANUS SP. some are metallic or pale. The abdomen
a distinctive, flattened, hemispherical These dark and robust is very bristly, especially toward ERIOTHRIX
head and colorful, patterned eyes. Most flies often mimic large bees, the rear. Many species look like RUFOMACULATA
are black, gray, or brown, with brightly such as the carpenter bee, in order bristly house flies (see muscids A native of Europe
marked abdomens, and measure to deter predators. p.567) and some species are almost
1⁄4 – 11⁄4 in (0.6 – 2.8 cm) in length. Females beelike. Adults feed on sugary fluids, and Central Asia, this
have bladelike mouthparts for cutting species parasitizes
skin; they feed on the blood of mammals caterpillars of tiger
and birds. Eggs are typically laid in a and ermine moths,

as well as lappet and
eggar moths.

parallel- mottled, bristles
sided angular on body
abdomen wings
TABANUS SUDETICUS
This giant horse fly has a beelike abdomen CHRYSOPS RELICTUS PHASIA HEMIPTERA TACHINA GROSSA bristles on I N V E R T E B R AT E S
with distinctive, pale, triangular marks down This twin-lobed deerfly inhabits bogs and ponds An inhabitant of meadows and Larger than most of its end of body
the middle. Some species transmit diseases in heather moorland in the Northern Hemisphere. woodland in parts of Europe, this relatives, this fly measures
to animals as well as humans. Its bite is very painful. species parasitizes shield bugs. 3⁄4 in (1.9 cm) in length. It is
found in Europe and Asia.

Family Tephritidae under the surface of fruit. Adults take Order Trichoptera
fluids, plant sap, nectar, or liquid from
Fruit flies rotting matter; the larvae are herbivorous. Caddisflies
Many species are crop pests.
Occurrence 4,500 spp. worldwide; on a range of plants, patterned There are about 10,000 species of caddisflies, in 43 families, and
crops, rotting matter wings they can be found almost anywhere there is freshwater. The adults
are slender, dull-colored insects, with a hairy body and wings, and
Habitat Terrestrial broad long antennae. The larvae are soft-bodied, and live in water, often
abdomen inside a protective, portable case, which each species builds in
Most fruit flies are under 1⁄2 in (1.5 cm) ICTERICA WESTERMANNI a characteristic way. They develop by complete metamorphosis.
long and recognizable by their Found in hedgerows, waste ground, and grassy
distinctive wing patterns, which places in Europe, this species of fruit fly feeds Family Limnephilidae Family Phryganeidae
can take the form of bands, on the flowerheads of ragworts.
patches, and zigzag markings. Northern caddisflies Large caddisflies
Females have a pointed ovipositor, which
can be longer than the rest of the body. Occurrence 1,500 spp. mainly in the Northern Occurrence 450 spp. mainly in the Northern
Males display to females by waving their Hemisphere; around lakes, temporary pools, ditches Hemisphere; near ponds, lakes, bogs, slow-moving
wings. Eggs are laid singly or in groups streams, rivers

Family Tipulidae HOLORUSIA SP. Northern caddisflies are reddish, Members of this family have light brown
This genus includes some of the yellowish, or dark brown, with dark or gray markings, and may look
Crane flies world’s largest crane flies. wing markings, and most are under 1 in mottled. They are 3⁄8 – 1 in (1.2 – 2.6 cm)
They have a wingspan (2.4 cm) long. Larvae eat organic detritus long and have at least 2 tibial spurs
Occurrence 15,000 spp. worldwide; usually in moist of 21⁄4 – 4 in and algae, and make cases from sand, on the forelegs and 4 on the mid- and
microhabitats pebbles, vegetation, or snail shells. hindlegs. Larvae make cases out of
front (6 – 10 cm). Adults may feed on liquids. plant fragments and fibers.
Habitat Terrestrial of head
elongated
Also known as daddy long legs, most
of these fragile, slender, and elongated long slender
flies measure 1⁄4 – 21⁄4 in (0.6 – 6 cm) in wings abdomen
length. They shed their legs very easily
if caught. The adults of many are short extremely long, LIMNEPHILUS LUNATUS PHRYGANEA GRANDIS
lived and feed on nectar and other fragile legs A widespread species, its larvae are found in This is the largest caddisfly found in the UK. The
fluids. The tough-bodied larvae, called a wide variety of freshwater habitats. Coloration male, smaller than the female (shown here), lacks
leatherjackets, live in soil, rotting ranges between drab shades of black and brown. the distinctive dark stripe on the wing.
wood, bird nests, and bogs, and are
a food source for many animals
and birds.

570 ARTHROPODS

Order Lepidoptera Family Bombycidae Family Geometridae

Moths and butterflies Silk moths Geometer moths

With over 165,000 species in 127 families, moths and butterflies Occurrence 100 spp. in tropical areas of Southeast Occurrence 30,000 spp. worldwide; on deciduous and
are among the most diverse insects in the world. They have Asia; on mulberry trees, other plants coniferous trees, woody shrubs, herbaceous plants
minute, overlapping scales on their bodies and wings, and
mouthparts in the form of a proboscis. There is no clear-cut Long valued as a source of silk, these The wings of these slender, generally
difference between butterflies and moths—and no scientific stout, pale cream, gray, or brown moths nocturnal moths are rounded, with
basis for separating them—but as a general rule, butterflies have wings that span 3⁄4 – 21⁄4 in (2 – 6 cm). a span of 1⁄2 – 3 in (1.4 – 7.4 cm), and
are brightly colored and day flying, with club-ended antennae, The smooth caterpillars have prolegs complex patterns of fine markings.
while moths are nocturnal and drab. In both, courtship often on all abdominal segments and usually The females of some species are
involves airborne scents and displays. The larvae, called a short, hornlike structure at the tail. wingless. These moths are colored
caterpillars, have cylindrical bodies and chewing jaws. Caterpillars of the commercial silk moth brown or green for camouflage;
They develop by complete metamorphosis, often forming feed on mulberry trees; other species coloration often varies between sexes.
inside a silk cocoon. feed on fig and related plants. Pupation Females lay eggs singly or in groups,
takes place inside a dense silk cocoon. on bark, twigs, or stems of host plants.
Family Arctiidae Functional mouthparts are absent in The characteristic looping motion of
adults, which do not feed. the caterpillars gives them the name
Tiger and ermine “loopers” or “inchworms.” Many species
moths conspicuous hairy, stout hooked are agricultural or forestry pests and
wing veins body wing-tips can cause severe damage.
Occurrence 11,000 spp. worldwide; in
well-vegetated areas where host plants occur

Habitat Terrestrial

I N V E R T E B R AT E S The hairy and heavy-bodied tiger moths pale orange margin BOMBYX MORI OOSPILA VENEZUELATA
are brightly colored. Ermine moths tend to on hind wings The silk moth originated in China but is now This green species is found mainly in
be pale with black spots or patches and ARCTIA CAJA cultivated in silk farms the world over. It is, the forests of Venezuela.
have a wingspan of 3⁄4 – 23⁄4 in (2 – 7 cm). Also called the garden tiger, this moth is however, extinct in the wild.
Caterpillars are herbivorous and many are highly unpalatable, and its bright, contrasting
poisonous. Adults take nectar and liquids. coloration advertises this to predators.
Recent evidence groups actiid and
noctuid moths together.

Family Hesperiidae club-ended Family Lycaenidae upper wing surfaces
antennae bright and iridescent
Skippers Blues, coppers, and
drab hairstreaks tails on
Occurrence 3,500 spp. worldwide except New Zealand; coloration hindwings
in open habitats such as cultivated fields and grassland Occurrence 6,000 spp. worldwide, particularly THECLA CORONATA
hindwing in warmer regions; in association with ant nests Also called the Hewitson’s blue hairstreak,
Heavy-bodied and mothlike, these tails or host plants this species inhabits tropical forests of South
butterflies get their name from their URBANUS PROTEUS America. It is one of the largest and most
rapid, darting flight. Most are drab The long-tailed skipper is common in The butterflies in this family are generally brilliantly colored members of the family.
brown with white or orange markings, parts of South and North America. It has small, with a wingspan of 1⁄2 – 2 in white rings
but a few can be brightly colored. Their characteristically long hindwing tails and (1.5 – 5 cm), but they are notable for color on antennae
wings span 3⁄4 – 31⁄4 in (2 – 8 cm). The an erratic flight pattern. differences between males and females.
antennae end in a long, curved, and Males often have brilliantly colored,
pointed club. Females lay single eggs communally in silk tents or webs that iridescent wing surfaces, while females
on host plants. Caterpillars are catch the sun’s rays. They pupate inside are generally dull. Most species have
herbivorous and feed at night. tough, egg-shaped, papery cocoons. squat caterpillars, which feed on plants
or small insects. Some produce a special
Family Lasiocampidae pale-bordered band fluid that is eaten by ants—in return, the
across forewings ants guard the caterpillar, and sometimes
Lasiocampids take it into their nest.

Occurrence 2,000 spp. worldwide except New Zealand; underside
on foliage of a wide range of deciduous trees

These insects, also known as lappet orange
and eggar moths, are heavy-bodied and markings
very hairy; most are yellowish brown, on forewings
brown, or gray. The wingspan is mostly of female
under 11⁄2 in (4 cm); females are bigger
than males. Eggs are laid in a band of short,dark- orange edge
100 – 200 around a twig of a host tree. edged tails to hindwings
The stout caterpillars may live
MALACOSOMA AMERICANUM THECLA BETULAE LYCAENA PHLAEAS
Also called the eastern tent caterpillar moth, this The brown hairstreak butterfly inhabits woodland The small copper butterfly is common in grassy
is an orchard pest. It inhabits forest and woodland in Europe and temperate Asia. The caterpillars areas up to 6,600 ft (2,000 m) in the Northern
areas in the northern USA and southern Canada. eat the leaves of sloe, plum, and birch trees. Hemisphere. The caterpillars feed on dock leaves.

INSECTS 571

Family Lymantriidae feed. The caterpillars are hairy, often Family Noctuidae and broad hindwings and are mostly
brightly colored, and feed in groups dull in color, although the hindwings
Tussock moths on foliage. They may induce an allergic Noctuid moths of some are brightly colored and
reaction if touched. patterned. The wingspan is usually under
Occurrence 2,600 spp. worldwide; on foliage Occurrence 35,000 spp. worldwide; on all types 2 in (5 cm). Females lay eggs singly or in
of deciduous and coniferous trees, shrubs distinctive, V-shaped of vegetation, including crops groups of 50 – 300, at the bases of host
mark on forewings plants or in the soil. These moths have
thoracic hearing organs to detect their
Tussock moths resemble noctuids broad, hairy body Almost every important main predators, bats.
(see right) and although most are LYMANTRIA DISPAR crop plant in the world
dull in color, tropical species can Commonly called the gypsy moth, this species is attacked by one or black wing markings
be colorful. The wingspan is 3⁄4 – 21⁄4 in is a native of Europe and Asia. Introduced to more noctuid moth
(2 – 6 cm); males are slightly smaller than North America to produce inexpensive silk, it species. These moths AGROTIS IPSILON
the females, which are sometimes escaped from captivity and has become a pest. have narrow forewings The dark sword-
wingless. Females lay eggs in clumps grass moth inhabits
on the bark of host trees and shrubs. dark, wavy line near crops and grassy
Adults lack a proboscis and do not margin of hindwings areas across the world.
Its caterpillars attack
Family Papilionidae caterpillars have a forked, fleshy scent scalloped wing potato, tobacco, lettuce,
gland, which emits an odor that markings and cereal crops.
Swallowtails protects them from predators.
They are herbivorous and eat a tails on ORNITHOPTERA PRIAMUS
Occurrence 600 spp. worldwide in warmer regions; range of foliage. Adult swallowtails hindwings Also called the Cairns birdwing, this species
in flower-rich, open or shaded areas feed on nectar and other liquids. PAPILIO GLAUCUS inhabits tropical forests in the Moluccas,
Commonly called the tiger swallowtail, this Papua New Guinea, the Solomon Islands,
This family includes birdwings— black-edged North American species inhabits woodland and northeastern Australia. Females are
the world’s largest butterflies, now orange spots and gardens. Its caterpillars feed among larger than males, and are drably colored.
protected by law. True to their name, on hindwings high foliage in many deciduous trees.
many swallowtail species have tails on bright green patterns
their hindwings. The wings are typically PARNASSIUS APOLLO on dark background
dark with bands, spots, or patches Also known as the Apollo, this species is
of white, yellow, orange, red, green, found in mountainous areas of Europe and black yellow abdomen I N V E R T E B R AT E S
or blue, and wingspan ranges from parts of Central Asia. wingspots
13⁄4 – 11 in (4.5 to 28 cm). Round eggs
are laid singly on host plants and
pupation also occurs here. The

Family Nymphalidae is 11⁄4 – 6 in (3 – 15 cm); the upper wing white patches DANAUS PLEXIPPUS
surfaces are brightly colored but the on head The monarch butterfly is famous
Nymphalid undersides have cryptic coloring for its long-distance migrations, the
butterflies to camouflage the butterfly at rest. white patches longest of which extends from Mexico to
Males and females may be differently around wing Canada. Its caterpillars feed on milkweed
Occurrence 6,000 spp. worldwide; in flower-rich colored, and there may be seasonal margins plants; a substance in these plants makes
meadows, woodland clearings variation. Females lay groups of rounded them unpalatable to predators.
eggs on the foliage of trees, shrubs, and distinctive MORPHO PELEIDES
This family includes some of the world’s herbaceous plants. The pupae often white spots Also called the common blue morpho,
most eye-catching butterflies, their most have warty, conspicuous bumps and on forewings this butterfly inhabits forests in South
characteristic feature being their very hang from the host plant by a group and Central America. With a wingspan
short, brushlike front legs, which have a of terminal hooks called cremasters. of 3 3⁄4 – 4 3⁄4 in (9.5 – 12 cm), it is
sensory function. These are held off the When young, the caterpillars may one of the larger nymphalids. Its
ground, close to the head. The wingspan feed communally on foliage. Adults
feed on nectar and liquids; some are caterpillars
pale spots on attracted to fruit, dung, carrion, can produce
margin of forewings urine, and even gasoline. a noxious
defensive odor.

dark bands
with white
marks
on wings

NYMPHALIS ANTIOPA broad, orange
Called the Camberwell beauty in the UK, bands
and the mourning cloak in North America, row of
this butterfly inhabits grassland in the purple-blue
Northern Hemisphere. spots
black-spotted
hindwings
VANESSA ATALANTA
The red admiral is widespread in the Northern
Hemisphere. Its caterpillars feed on nettles and hops.

572 ARTHROPODS

Order Lepidoptera continued or in groups of 20 – 100 on host plants. distinctive,
The pupae, which have a distinctive, orange tip
Family Pieridae spiny projection on the head, are held on male’s
upright on the host plant by a silk belt. forewings
Whites and sulphurs
black spot
Occurrence 1,200 spp. worldwide; anywhere, on forewings
often in groups at bird droppings, urine, or puddles
in sunshine

The wings of these very common orange ANTHOCHARIS CARDAMINES PIERIS NAPI dark wing
butterflies are usually white, yellow, spot on The orange tip inhabits damp, grassy meadows and The green- margins
or orange, with black or gray markings. hindwings open woodland in Europe and temperate Asia. The veined white
The wingspan is 3⁄4 – 23⁄4 in (2 – 7 cm) undersides of the hindwings are dappled pale green. inhabits grassy,
and the pigments in the wing scales are COLIAS EURYTHEME open areas and
derived from by-products of the food Also called the orange sulphur or the alfalfa sulphur, this cultivated land in
eaten by caterpillars. Eggs are laid singly species inhabits grassy, open areas and cultivated land in North Europe, Asia, and
America. Caterpillars feed on clover and can be pests of alfalfa. North America.

Family Crambidae Family Saturniidae curved broad, feathery
wing-tip antennae
Grass moths Saturniid moths of male

I N V E R T E B R AT E S Occurrence 10,000 spp. worldwide, especially in Occurrence 1,500 spp. worldwide, especially in ATTACUS ATLAS triangular black,
warmer regions; on a range of plants, from aquatic wooded tropical and subtropical regions; on foliage This Southeast Asian translucent wavy line
plants to trees moth, commonly called patches on on wing
Variously known as emperor, moon, the Atlas moth, has the wings margins
Some species of grass moths have royal, and atlas moths, these are large largest wing area of any eyespots
a short “snout” on the front of their and often spectacular insects with broad, insect. It inhabits forest CALLOSAMIA on forewings
head. Most are drably colored. Their often conspicuously marked wings. The and open, grassy areas. PROMETHEA
wings span 2 – 12 in (5 – 30 cm), and the Although easy to raise, it long tail The promethea
wings span 3⁄8 – 13⁄4 in (1 – 4.6 cm); center of each may have an eyespot; is vulnerable and protected with red moth inhabits
the forewings may be broad or some species have hindwing tails. in some countries. border woodland and
narrow, but the hindwings are Males have broad, feathery cultivated areas
broad and rounded. or comblike antennae. Fully dark border across of southern Canada
Eggs are laid on grown caterpillars make dense forewings and and the USA. Females
the undersides cocoons, attached to the twigs body are heavy bodied and
of leaves. of host plants, and feed on the nocturnal; males are
foliage of a wide range of trees large, dark, day flying, and
long fringe and shrubs. Adults do not feed. furry body resemble Nymphalis
on hindwings antiopa (see p.571).
CHILO PHRAGMITELLA ACTIAS LUNA
The Wainscot veneer is found in reed beds, The American moon moth is found
where its caterpillars feed on the stems of from Mexico to the Canadian border.
reeds belonging to the genus Phragmites. The caterpillars feed on the leaves of
deciduous trees.

Family Sesiidae Family Sphingidae distinctive dark dark triangles
green forewings on forewings
Clear-winged moths Hawk moths
EUCHLORON MEGAERA
Occurrence 1,200 spp. worldwide, especially in Occurrence 1,450 spp. worldwide, especially in tropical Also called the verdant
northern temperate regions; around flowers or near and subtropical regions; on foliage sphinx, this hawk moth
host plants inhabits forests and
With their streamlined bodies and woodland of Africa south
These usually diurnal moths resemble long, narrow wings, hawk moths of the Sahara. Its caterpillars
wasps or bees; some even pretend to are among the fastest flying eat vines and creepers.
sting. They are black, bluish, or dark insects, reaching speeds of
brown, with yellow or orange markings. over 30 mph (50 kph). Their wings drably mottled black and white orange, red,
The wings, large areas of which are measure 11⁄2 – 6 in (3.5 – 15 cm) from forewings marks at base black, and
transparent, span from 1⁄2 – 11⁄2 in (1.4 to tip to tip. Adult hawkmoths mostly of forewings white patches
4 cm) and produce a buzzing sound in suck nectar—some hovering like skull mark long, robust, on hindwings
flight. Many species are pests of hummingbirds as they do this. on thorax green body
fruit and other They have a long, curled proboscis,
trees and up to 10 in (25 cm) long. Although ACHERONTIA ATROPOS elongated forward-swept
shrubs. some species are diurnal, most are The death’s head hawk moth is named for the body wings
active after dark. Hawkmoths often skull-like marking on its thorax. It is found PROTAMBULYX EURYALUS
transparent migrate long distances to breed. Their in Africa and Asia, but also migrates to Europe. This species is found in South
areas on wing caterpillars are known as hornworms, America. Both sexes are very
because they have a spinelike process similar in appearance.
SESIA APIFORMIS at the end of the abdomen. Some are
With its transparent wings, the hornet moth, from very serious crop pests.
Europe and Asia, convincingly mimics a hornet.
Its caterpillars bore inside willows and poplars.

INSECTS 573

Family Tineidae Family Tortricidae Family Uraniidae LYSSA ZAMPA
This large, Southeast Asian moth has a
Clothes moths Tortricid moths Uraniid moths wingspan of 4 – 41⁄4 in (10 – 10.6 cm), a little
and relatives larger than most species in the family.
Occurrence 10,000 spp. worldwide; on leaves, shoots, Occurrence 700 spp. in tropical and subtropical
Occurrence 2,500 spp. worldwide; in rotting wood, buds, fruit regions; on plants, especially euphorbias forewings have
fungi, dried organic matter, woollens, fabrics, dry pointed tip
foodstuffs These small moths are also known This family includes large, long-tailed,
as bell moths. While most are brown, colorful, day-flying moths with iridescent
Many of these small, drab moths green, or gray, and patterned to blend iridescent wing scales, and dull, markings
are pests, and are variously known as in with bark, lichen, and leaves, some nocturnal species without tails. The
grain moths, case-bearing moths, and can be brightly colored. Their head South American and Malagasy species
tapestry moths. Typically dull brown is covered with rough scales. The are so colorful and large that they are
in color, some have a shiny golden wingspan is 5⁄16 – 11⁄2 in (0.8 – 3.4 cm) and often mistaken for butterflies. The
appearance. Their head has a covering the forewings, unusually rectangular, wings typically span 21⁄4 – 4 in (6 – 10 cm).
of raised, hairlike scales or bristles and are held rooflike over the body at rest. Adults are often migratory, sometimes
the proboscis is short or absent. The A female can lay up to 400 eggs in forming large swarms, in response to
wings, 5⁄16 – 3⁄4 in (0.8 – 2 cm) across, are a week, singly or in small groups, changes in larval food quality. The
narrow and are held at a steep angle on the surface of fruit or leaves. The caterpillars of many species eat plants
over the body at rest. Females lay caterpillars feed on leaves, shoots, of the family Euphorbiaceae. They avoid
30 – 80 eggs over a period of 3 weeks. and buds of plants and often tie or ant predation by dropping from leaves
Caterpillars are saprophagous. Some roll leaves with silk. Being fruit- and on silk lines.
of them make portable cases of silk and stem-borers or gall-formers, many
debris, others make a silk web wherever species are pests that cause damage
they feed. Adults do not generally feed. to trees and fruit crops.
Many species will not readily fly,
scuttling away from danger instead. forewings have
camouflage coloring

TINEOLA BISSELLIELLA pale hindwings ALCIDES METAURUS hindwings CHRYSIRIDIA RHIPHEUS I N V E R T E B R AT E S
Also known as the common clothes moth, this with long fringe This day-flying zodiac moth from the rain have distinct Also known as the Madagascan
widespread species inhabits clothing, carpets, and CLEPSIS RURINANA forests of North Queensland, Australia, spotting and sunset moth, this is a brightly colored
furs. The female lays eggs in the folds of clothes. Found in woodland and forests of Europe and feeds on flowers during the day and flies 3 tails day-flying species that inhabits
Asia, the caterpillars of this species roll the back to the canopy in the evening. woodland and forests of Madagascar.
leaves of deciduous trees and feed inside.

Order Hymenoptera Family Apidae wax, and pollinate most of the world’s
plants. Typically, they are 1⁄8 – 1 in
Bees, wasps, ants, and sawflies Honey bees (0.3 – 2.7 cm) long. Most females have a
and relatives venomous sting and a basket to carry
The order Hymenoptera is a vast group of insects that contains pollen on the hindlegs. Honey bees and
about 198,000 species in 91 families. It is divided into 2 suborders: Occurrence 5,700 spp. worldwide; in all well- bumble bees are social insects, living in
plant-eating sawflies (Symphyta); and wasps, bees, and ants (Apocrita), vegetated, flower-rich areas complex colonies consisting of a queen,
which—unlike sawflies—have a narrow “waist” and, in females, an males, and sterile female workers. The
ovipositor that may sting. Most species have 2 pairs of membranous This family includes one of the world’s honey bee nest is a vertical array of wax
wings, joined in flight by tiny hooks. Ecologically, these insects are of most useful insects—the honey combs divided into thousands of cells
tremendous importance in acting as predators, parasites, pollinators, bee—together with orchid bees and for rearing the young and storing pollen
or scavengers. Social Hymenoptera, including ants and bees, are the bumble bees. They provide honey and and honey. Queens may lay more than
most advanced insects on earth. 100 eggs a day. Bumble bee nests are
made of grass with wax cells, and the
Family Agaonidae queens raise fewer offspring.

Fig wasps queen

Occurrence 750 spp. in subtropical and tropical drone
regions; on fig trees

Fig wasps have evolved a symbiotic worker
relationship with fig trees. The female
wasps, no more than 1⁄8 in (3 mm) long, BLASTOPHAGA PSENES BOMBUS TERRESTRIS APIS MELLIFERA
crawl inside figs, which are lined with The common fig wasp is found in Asia, southern Like all its relatives, the European buff-tailed Originally from Southeast Asia, the honey bee is
tiny flowers. They pollinate some flowers, Europe, Australia, and California. It pollinates bumble bee has a body covered by “fur,” enabling now raised all over the world. A honey bee colony
and lay eggs in others. After developing, Ficus carica, the common fig. Females are 20 it to fly in the cool conditions of early spring. has strict division of labor. The queen lays all the
the wingless males fertilize the females, times more common than males. colony’s eggs, while the workers gather food and
which fly away to find new trees. tend the larvae. The queen is fertilized by a drone.

574 ARTHROPODS

Order Hymenoptera continued Family Chalcididae Family Chrysididae wasp larva then feeds on the host larva
Family Braconidae and also eats the host’s provisions. The
Chalcid wasps Jewel wasps adults feed on nectar and liquids.
Braconid wasps
Occurrence 1,800 spp. worldwide; on suitable Occurrence 3,000 spp. worldwide; on suitable bright
Occurrence 20,000 spp. worldwide; on suitable insect hosts insect hosts metallic
caterpillar hosts coloration

Like ichneumon wasps (see below), Mostly under 5⁄16 in (8 mm) long, chalcids Jewel wasps, also known as cuckoo or
make up a small but important family of ruby-tailed wasps, have very hard and
braconids are parasitoids—animals that parasitic insects. Many species lay their dimpled bodies that protect them from
eggs in beetle larvae, or in the caterpillars bee and wasp stings. They are 1⁄16 – 3⁄4 in
develop inside a living host, eventually of butterflies and moths, but some are (0.2 – 2 cm) long. Most species are a very
hyperparasites, attacking the eggs or bright metallic-blue, green, or red, or
killing it. Braconids mainly attack the larvae of other parasitic insects. Adult combinations of these colors. The distinctive
chalcids are typically dark brown, black, abdomen is hollowed underneath, lobe on
caterpillars of moths and butterflies, red, or yellow, sometimes with a metallic allowing the wasp to curl up if attacked. hindwings
sheen. Their larvae—like those of other Typically, the female lays an egg in the
often laying over 100 eggs on or in their wasps—are white and grublike, without nest of a solitary bee or wasp, and the
legs. Some chalcid species are bred and larva immediately hatches. The jewel
victims. The developing larvae feed on released to control insect pests. end of abdomen hard, dimpled
Family Cynipidae metallic-purple body surface
the caterpillar’s tissues, pupate, and slight vein pattern
on wings Gall wasps
fly away as adults. Adult braconids are
Occurrence 1,250 spp. mostly in the Northern
typically less than 7⁄32 in (7 mm) long, and Hemisphere; on trees, plants STILBUM SPLENDIDUM
The splendid emerald wasp is a North Australian
reddish brown or black. Many species species that parasitizes solitary mud-nesting wasps.

are used as biological controls against

insect pests. long species-specific galls on oaks and
smoky antennae related trees by laying eggs inside the
wings plant tissue. The galls protect and
nourish the developing larvae. Life
I N V E R T E B R AT E S metallic-blue broad, cycles of gall-forming species involve
abdomen rounded sexual and asexual generations.
ovipositor head
of female ANDRICUS SP.
curved enlarged hind These gall wasps are widespread
BATHYAULAX SP. hind femora in Europe, and use various
Larger than most of its family, tibiae oak trees as their hosts.
these braconids measure 1⁄2 – 3⁄4 in ( 1.5 – 2 cm), Gall wasps are shiny, reddish brown
and are found in Africa and Southeast Asia. punctured body or black, and usually fully winged. They shiny, punctured
They are used to control stem-boring caterpillar surface measure 1⁄32 – ⁄11 32 in (1 – 9 mm) in length; surface
pests of cereal crops. CHALCIS SISPES males are usually smaller than females.
This species is native to Europe and Asia. Its The latter have a laterally flattened shiny, smooth
larvae parasitize the larvae of soldier flies. abdomen and a humped thorax. Many abdomen
species, by a process not yet fully
Family Ichneumonidae slender understood, induce the growth of
antennae
Ichneumon wasps Family Mutillidae
black and Family Mymaridae
Occurrence 60,000 spp. worldwide, especially yellow wing Velvet ants
temperate regions; wherever suitable insect hosts patterns Fairyflies
are found Occurrence 4,000 spp. worldwide, especially
subtropical and tropical regions; females found Occurrence 1,400 spp. worldwide; in a wide variety
in dry habitats of habitats, wherever insect hosts are found

Ichneumon wasps are of great ecological ovipositor Despite their name, these are not ants. The smallest flying insects on earth
importance, because they parasitize belong to this family. Fairyflies are
other insects, including many pests. PARACOLLYRIA SP. The name velvet ant comes from the 1⁄16 – 3⁄16 in (0.2 – 5 mm) long, and are
Using their slender ovipositors, the These African wasps have a bright coloring that dark brown, black, or yellow. The
females lay eggs in the larvae and pupae works as a warning to predators and is soft, velvety hairs that cover the antlike, narrow front wings have a fringe of
in a wide range of hosts, sometimes mimicked by other insects. hairs but no obvious venation. The
drilling through several inches of wood wingless females; males have fully hindwings appear stalked, and are
to reach them. Upon hatching, the swollen antennal strap shaped. The females of all
ichneumon larvae eat their hosts segments developed wings. Velvet ants are species parasitize the eggs of other
from inside. Adult ichneumons insects, mostly of plant-hoppers and
measure 1⁄8 – 11⁄2 in (0.3 – 1⁄8 – 1 in (0.3 – 2.5 cm) long. They use the other bug families. Several fairyfly
4.2 cm) long, and are species are used as biological control
typically slender, with larvae of other wasps or bees as food agents against insect pests.

a narrow waist. for their larvae. Females bite open a

suitable host cell and, if the larva

in it is fully grown, lay their eggs

on it and reseal the cell. The

larvae then eat the host larva,

marks on and pupate inside the
abdomen
long cell. Female velvet ants dimpled
antennae black have powerful stings. thorax
pterostigma
(cell) on female is
forewings wingless

long reddish orange
ovipositor legs markings on
for drilling hind femora
wood black MUTILLA EUROPEA
rear half of The European velvet
RHYSSA PERSUASORIA abdomen ant, widespread in ANAGRUS OPTABILIS
The giant ichneumon wasp uses its the warmer regions This is a specialized parasitoid of the eggs of
long, drill-like ovipositor to reach the larvae JOPPA ANTENNATOR of Europe, parasitizes certain plant-hoppers. Related species have been
of horntail sawflies deep in pine lumber. This species is characterized by swollen antennal species of bumble bee. used to control plant-hoppers that attack rice crops.
segments and contrasting, wasplike coloration.

INSECTS 575

Family Pompilidae sealing the nest. Spider-hunting wasps Family Sphecidae soil, or rotten wood. The female catches
have a painful sting. Most species are an insect or a spider, paralyzes it, and
Spider-hunting dark blue or black (although the wings Digger wasps buries it in a nest where she lays her egg.
wasps may be dark yellow), and measure In this way, the emerging larva has a
3⁄16 – 31⁄4in (0.5 – 8 cm) long. Males are Occurrence 8,000 spp. worldwide; in a variety ready supply of food.
Occurrence 5,000 spp. worldwide, especially smaller than of microhabitats—plant stems, soil, rotten wood
tropical and subtropical regions; wherever spider the females. wings held flat
hosts are found over body

True to their name, these wasps can amber wings
paralyze spiders with their strong venom.
Females fly or run along the ground in POMPILUS SP. Some species of this family are
search of spiders, drag the immobilized This genus is common
spider to a nest prepared in mud or in a in warm regions, also known as solitary hunting
crevice, and lay a single egg on it before particularly where the
ground is sandy. Like wasps, sand wasps, or mud
other spider-hunting
wasps, Pompilus dauber wasps. They are blue-green, metallic
wasps are solitary. coloration
5⁄32 – 13⁄4 in (0.4 – 4.8 cm) spiny AMPULEX COMPRESSA
long, relatively hairless, and legs This African species, known as the emerald

yellow visible often brightly colored. Digger wasps cockroach wasp, hunts cockroaches. It may
patches male
on abdomen genitalia are solitary, and nest in plant stems, enter houses in search of its quarry.

smoky wing antennae curl matt black Family Scoliidae egg on each larva. The wasp larva
border after death body pupates in a cocoon that it spins inside
Mammoth wasps the beetle larva’s remains.

Occurrence 500 spp. worldwide, especially in tropical
regions; wherever scarab beetle hosts are found

amber smoky wings As their name suggests, these are large wrinkles I N V E R T E B R AT E S
wings with purple tint wasps, measuring 3⁄8 – 21⁄4 in (1 – 5.6 cm) in at end of
length, with stout bodies that are densely wings
large spurs spurs covered with hair. They are bluish black
on hind on tibiae with reddish brown markings. Males are hairy
tibiae MACROMERIS VIOLACEA smaller and slimmer than females, with legs
PEPSIS HEROS The violet spider-hunting wasp, named for its longer antennae. After mating, females SCOLIA PROCERA
The tarantula hawk is the largest spider- iridescent purplish wings, is found in Southeast hunt for the larvae of scarab beetles. Found in Java, Borneo, and
hunting wasp, up to 31⁄4 in (8 cm) long. As Asia. It is 2 – 21⁄4 in (5 – 5.5 cm) long. They then sting, paralyze, and lay a single Sumatra, wherever scarab beetle larvae exist; this
its name suggests, it preys on tarantulas. insect has a painful sting but is not very aggressive.

Family Vespidae insects by sterile female workers. The Family Siricidae Family Tenthredinidae
adult wasps, which measure between
Social wasps 5⁄32 and 11⁄2 in (0.4–3.6 cm) in length, roll Horntails Common sawflies
or fold their wings longitudinally, rather
Occurrence 4,000 spp. worldwide; found in a variety than hold them flat over the body. Nearly Occurrence 150 spp. in temperate areas of the Occurrence 6,500 spp. worldwide, except New
of habitats, in nests and foraging widely for prey all social wasps have warning coloration. Northern Hemisphere; on and near deciduous and Zealand; on a wide range of plants in gardens, pastures,
They can also have a painful sting. coniferous trees woodland

The most familiar social wasps are wings folded warning Horntails or woodwasps are the Sawflies often look like wasps, but are
the paper wasps and yellow jackets, longitudinally coloration largest members of the sawfly suborder more primitive insects, classified in a
which make nests out of chewed wood (see right). Despite their menacing suborder of their own. Unlike wasps,
or other fibers. The queen overwinters, VESPA VULGARIS appearance, they do not sting—the bees, and ants, they do not have a
makes a nest in spring, and raises the Also called the common “horn” at the end of their abdomen is narrow waist, do not sting, and are
first brood herself. Workers cooperate wasp, this wasp is a useful a harmless spine. They are reddish solitary. Common sawflies are 1⁄8 – 3⁄4 in
with her in caring for subsequent garden species since it (0.3 – 2.2 cm) long. The females use their
broods. Larvae develop in horizontal removes caterpillars and other brown, black and yellow, or metallic- ovipositor to lay eggs in plants, and
“combs,” and are fed chewed-up pests. It makes its nest from purple, and measure 3⁄4 – 11⁄2 in the caterpillar-like larvae, which are
wood fibers. (1.8 – 4.2 cm) in length. Females sometimes brightly colored, usually feed
large in the open on leaves. Common sawflies
compound eyes have a long ovipositor and use it to often attack fruit, vegetables, and trees,
lay their eggs inside tree trunks, in and can be highly
yellow patches black dots the process infecting them with fungi. destructive pests.
on thorax on abdomen Larvae burrow into heartwood and eat
fungus and wood. Pupation occurs in long, narrow,
a cocoon of silk and chewed wood. yellow wings

yellow patch large, black
behind eye and yellow body

spine

wasplike, yellow
black and yellow hindlegs
abdominal stripes

VESPA CRABRO VESPULA GERMANICA UROCERUS GIGAS TENTHREDO SCROPHULARIAE
Commonly known as the European hornet, Colonies of the German wasp may be perennial, The horntail shown above is a female common This figwort sawfly is a wasp-mimicking
this wasp makes its nest in hollow trees. Its with more than one queen. This wasp lives horntail or giant woodwasp. The male of this species, found in Europe and Asia. Its larvae
colonies have only a few hundred workers. mostly in the Northern Hemisphere and was harmless species is elusive. feed on mullein and figwort plants.
introduced to North America in the late 1800s.

576 ARTHROPODS

Order Hymenoptera DIFFERENT CASTES ON THE DEFENSIVE
This worker wood ant,
Family Formicidae and the females lose their wings. A colony will contain 3 castes of ants: workers, Formica rufa, has taken
All ants have glands that secrete a defensive posture with its
Ants pheromones—chemical messages used which are always wingless sterile females, queens, jaws wide open and abdomen
for communication between colony curled under and forward.
Occurrence 12,000 spp. worldwide; in virtually all members as well as for trail making and and males (which are usually winged and form In this position, it will be able
regions except in Antarctica and on a few oceanic islands defense. Numerous species of insects to spray formic acid toward
and plants have evolved symbiotic and mating swarms with queens at certain times of the an attacker.
Habitat Most terrestrial habitats often highly complex relationships with
ants. In some cases, plants provide year). The physical differences between the castes
Ants are found almost everywhere on ants with food or homes; in return,
Earth and have an immense impact the ants may protect the plants by of the African driver ant Dorylus nigricans (shown
on terrestrial ecosystems. In many, ants disturbing potentially damaging
move more earth than earthworms and herbivores, or stripping leaves from here at relative sizes) are typical
are vital in nutrient recycling and seed encroaching vines. The ant family is
dispersal. Like termites and some bees divided into 10 distinct subfamilies, of most ants, although queens
and wasps, ants are highly social and of which the biggest by far are the
live in colonies ranging from a handful Myrmicinae and the Formicinae. in this species are wingless. sausage-
of individuals sharing a tiny shelter to Some myrmicine ants have stings, MALE ANT shaped
tens or hundreds of millions inhabiting while formicines defend themselves Because of its body shape, the body
structures reaching 20 ft (6 m) below by spraying formic acid. The infamous
ground. Two or more generations of driver and army ants of tropical regions male is called a sausagefly.
ants overlap at any one time, and belong to the subfamily Dorylinae. Their Males are often attracted
adults take care of the young. There colonies move in massive columns, up to lights after dark.
are different classes (or castes) of ants to several million strong, often raiding
within a colony, each with a specific termite or ant nests. FEMALE WORKERS
task to perform: some are workers, Worker ants are all
who also defend the nest; others female. Large workers
are dedicated to reproduction. Caste carry items of prey,
is determined by diet: a rich diet while the smaller broad
producing reproductives, a poor workers tend to forewings
one producing sterile workers. Mating
may take place on the wing or on the carry liquid. large
ground, after which the males die abdomen
QUEEN ANT
The queens of this
species are the
largest of any ant
and can lay 1 – 2
million eggs every month.

I N V E R T E B R AT E S constricted
waist

elbowed WINGLESS FEMALE
antennae Sterile, wingless females do the work
of the colony, and in some species
EATING HABITS chewing may show amazing adaptations
mouthparts to the head and jaws for crushing
Some ants are herbivorous seed seeds, blocking nest entrances,
gatherers or fungus eaters.
Other species are carnivorous dismembering enemies,
or omnivorous, while some rely and other purposes.
exclusively on the honeydew
produced by sap-sucking bugs.

WORKERS WITH PREY
Worker wood ants, Formica rufa, may
cooperate in dragging a large item of prey
back to the nest, where it will be cut up.

large worker

LEAFCUTTERS
Leafcutter ants, Atta spp., chew pieces of
leaves into pulp, which they use to fertilize
fungus beds—their sole source of food.

577 I N V E R T E B R AT E S

578 ARTHROPODS

Centipedes and millipedes

PHYLUM Arthropoda Centipedes and millipedes are terrestrial arthropods with many
SUBPHYLUM Mandibulata legs, each of their numerous body segments carrying one or
SUPERCLASS Myriapoda 2 pairs. Their heads have biting mandibles and a single pair
of antennae. Far less abundant and diverse than insects,
CLASSES Chilopoda
Diplopoda they are confined to humid microhabitats because they
do not have a waterproof cuticle. However, like
ORDERS 21 insects, they breathe by taking gases directly
FAMILIES 171 into the body through openings in the cuticle.
SPECIES About 13,150 Centipedes have a single pair of legs on

each trunk segment. They can run fast,

although some soil-living species move slower. They are

carnivorous and have venomous claws to kill prey.

Millipedes are all slow moving, with elongated,

cylindrical bodies. Most of their trunk segments are DEMOXYTES PURPUROSEA

fused together in pairs, called diplosegments, each This species was described in 2007 from Thailand and belongs
to a genus of spiny “dragon” millipedes. Like many large
bearing 2 pairs of legs. They are mostly herbivores millipedes, the shocking pink dragon millipede secretes bitter—
and poisonous—hydrogen cyanide when molested by predators.
or scavengers, using their toothed mandibles to chew The startling color serves as a warning to any would-be attacker.

rotting organic matter, soil, plants, algae, and moss.

I N V E R T E B R AT E S Class Chilopoda Class Diplopoda

CENTIPEDES MILLIPEDE

Elongated and flattened, centipedes have a trunk made up of at Despite their name, millipedes never have a thousand legs. Some
least 16 segments, most of which carry one pair of legs; the last pair of have as many as 750, but even these species are slow runners. To
walking legs is always longer than the rest. Most species are yellowish defend themselves, most millipedes rely primarily on their tough
or brownish, and all have fine, sensory hairs on the body. There are 5 exoskeletons, which are reinforced by calcium carbonate. When
orders, 24 families, and 3,149 species. touched, many also coil up or produce toxic chemicals. This class
has 9,973 species, classified in 16 orders and 147 families.

Family Lithobiidae with 7 pairs of legs and add a leg- Family Julidae Family Glomeridae
bearing trunk segment at each molt.
Lithobiids Lithobiids have a lifespan of 5 to 6 years. Cylinder millipedes Pill millipedes

Occurrence 975 spp. worldwide, especially in dark brown broad head Occurrence 900 spp. in the Northern Hemisphere; in Occurrence c.200 spp. in warm and cool temperate
temperate regions of the Northern Hemisphere; trunk soil, leaf litter, caves, under stones and rotting wood regions of the Northern Hemisphere; in soil, caves
in cracks, crevices segments

Lithobiids are mostly reddish light and venomous These millipedes have rounded Measuring 1⁄16 – 3⁄4 in (0.2 – 2 cm) in length,
brown but some can be brightly dark bands claws bodies that can range from 5⁄16 – 31⁄4 in these broad-bodied millipedes are either
colored. The tough and on rear legs LITHOBIUS VARIEGATUS (0.8 – 8 cm) in length. Most are small and drably colored or large and
flattened body is 1⁄4 – 13⁄4 in The banded stone centipide dull-colored but a few have red, cream, brightly marked. The trunk is made up
(0.6 – 4.5 cm) long. There are inhabits leaf litter in Europe’s or brown spots. The antennae are fairly of 13 segments, and the shape of the
15 pairs of legs, and threadlike deciduous woodland. It does long and slender. As in all millipedes, dorsal plates allows the millipede to roll
antennae with 75 – 80 segments. climb trees in search of food but the females lay their eggs in nests in into a tight ball if threatened. Adults have
The young emerge from the egg most often sits and waits on the soil. There are typically 7 nymphal 15 pairs of legs. Eggs are laid in soil, and
ground for prey to pass by. stages. Cylinder millipedes are common when the young hatch, they initially have
in Europe and Asia. only 3 pairs of legs. Some members of
Family Scolopendridae stripes or bands. They have 21 or 23 this family, such as Glomeris species,
pairs of legs, and threadlike antennae TACHYPODOIULUS NIGER may live up to 7 years.
Scolopendrids with fewer than 35 segments. Usually, This species is commonly known as the black
there are 4 ocelli, or simple eyes, on snake millipede. It has a black trunk and white GLOMERIS MARGINATA
Occurrence 400 spp. worldwide, especially in either side of the head. Females lay their legs, and is up to 2 in (4.8 cm) long. It inhabits The white-rimmed pill millipede can be found
subtropical and tropical regions; in soil, leaf litter, eggs under soil, rocks, or loose bark. woodland in Western Europe and climbs walls, in soil and leaf litter in Europe, and parts of Asia
cracks, crevices trees, or shrubs to feed after dark. and North Africa. When completely rolled up, it
yellow contrasting venomous can be confused with the pill woodlouse (see
The largest centipede in the legs bands of claws p.584), although it has a shinier body.
world, Scolopendra gigantea color
from South America, belongs
to this family. The body length of SCOLOPENDRA HARDWICKEI
scolopendrids ranges from 11⁄4 – 12 in Tiger centipedes owe their common name to
(3 – 30 cm). Nocturnal hunters, they are the markings on their body and their predatory
robust enough to catch and kill mice habits. They are found in Southeast Asia, living
and frogs with their venomous claws, under stones, rotting wood, and loose bark.
the smaller species being the most
deadly. Scolopendrids are typically
brightly colored and may be yellow, red,
orange, or green, often with dark

CRUSTACEANS 579

Crustaceans

PHYLUM Arthropoda Crustaceans are a very diverse group, ranging from water fleas Small crustaceans may simply graze
SUBPHYLUM Mandibulata and copepods—only just visible to the naked eye—to heavy-bodied on particles of sediment, taking
SUPERCLASS Crustacea crabs and lobsters, which include the largest arthropods alive microorganisms from the surface.
today. Although some crustaceans, such as woodlice, have
CLASSES 7 successfully adapted to life on land, the vast majority of species Life cycle
ORDERS 56 live in freshwater or in the sea. Aquatic crustaceans include some
FAMILIES About 1,000 of the most abundant animals on earth, and they play a key part in Most species of crustaceans have
SPECIES About 70,000 many food chains. separate sexes. They copulate, lay
eggs, and brood the eggs, either
Anatomy Crustacean appendages—what Feeding within a brood chamber or attached
we commonly understand as “legs”— to their legs. Typically, eggs hatch
Crustaceans differ from insects, have 2 branches and are specialized Crustaceans show a wide range into tiny larvae that float away in
centipedes, and millipedes in a for a number of functions such as of feeding strategies. Most large the water, feed, and grow, developing
number of ways. They have 2 pairs movement, sensing the environment, species capture their prey and kill trunk segments and legs.
of antennae, compound eyes on respiration, and egg brooding. The first it by stunning, crushing, or tearing it
stalks, and a cuticle that is often pair of thoracic legs may be enlarged apart. Many species are filter feeders:
strengthened with calcium carbonate, to form chelipeds, with strong claws they use their thoracic appendages
especially in larger species. The head that are used for defense, handling to set up currents in the water and
and thorax are often covered by a food, and even sexual signaling. The filter small particles of food, which
shield, or carapace, and the front of thoracic appendages, called are amassed and pushed into the
this usually extends to form a projection pereopods, typically have gills. The mouth. Krill feed while swimming
called the rostrum. The thorax has a basal part of some appendages helps and trap particles in hairlike structures
variable number of segments. The in walking, while the abdominal called setae on their thoracic legs.
abdomen ends in a tail-like telson. segments usually carry paired
In crabs, the abdomen is short, flat, swimming appendages called I N V E R T E B R AT E S
and tightly curled around to fit under pleopods, or swimmerets.
the broad carapace.

RED CRAB MIGRATIONS

Christmas Island, in the Indian Ocean, has a population
of about 100 million red crabs. Each year, triggered by the
first rains of the wet season, they migrate from their inland
habitats to mate and spawn by the coast. The males, which
arrive first, dip themselves in sea water to replenish lost salt
and moisture. After mating, females remain by the sea for
about 2 weeks, waiting for the eggs to mature before
releasing them along the coast.

Class Branchiopoda of antennae and the second pair lateral, large, branched
of mouthparts (maxillae) are small. compound antennae used
Branchiopods The appendages have a flat, eyes on stalks for locomotion
leaflike appearance, and carry leaflike
Occurrence c.1,000 spp. worldwide; mainly in fringes of fine bristles for filtering appendages indistinct body
freshwater bodies, some in saline or marine conditions particles of food from the water. BRINE SHRIMP segmentation
Branchiopods swim either Found worldwide, WATER FLEA
Branchiopods comprise 4 orders: rhythmically, using their except in the Arctic Using their branched,
tadpole shrimps (Notostraca), water appendages, or jerkily, using the and Antarctic, brine shrimps feathery antennae-like oars, water
fleas (Clacodera), clam shrimps second pair of antennae. Many (family Artemiidae) live in saline fleas (family Daphniidae) swim jerkily
(Conchostraca), and brine shrimps species possess the respiratory lakes and pools. Their life cycles are rapid, through lakes and ponds. In many areas,
(Anostraca). There are 25 families. pigment hemoglobin and may suiting them to habitats that can dry up quickly. these tiny crustaceans undergo a population
Although some branchiopods reach appear pink as a result. Females Like all brine shrimps, members of the genus explosion every spring, providing a huge
a length of 4 in (10 cm), most species may produce more than one batch Artemia, such as the one shown here, lay eggs supply of animal food for fishes. The species
are much smaller. The body may be of eggs, each consisting of up that can be dormant for up to 5 years. above belongs to the genus Daphnia.
covered by a shieldlike carapace,which, to several hundred eggs. In
in some species, takes the form of a some species, these are
2-halved (bivalvate) shell. The first pair very drought resistant.

580 ARTHROPODS

Class Ostracoda of the body. All species have a single CYPRIDID MUSSEL SHRIMPS CYPRIDINID MUSSEL SHRIMPS
simple eye, the nauplius eye, in the Found in lakes, pools, and swamps, cypridid The largest mussel shrimps, including the
Mussel shrimps middle of the head; some also have a mussel shrimps (family Cyprididae) include deep-sea genus Gigantocypris, belong to this
pair of compound eyes. Most species the majority of freshwater species. Some swim, widespread, marine group (family Cypridinidae).
Occurrence 5,400 spp. worldwide; in marine, brackish have separate sexes, which mate in while others crawl on the bottom. They often Cypridinids are good swimmers. They propel
water, freshwater bodies, a few species are terrestrial order to reproduce; however, some reproduce parthenogenetically, and in some themselves with their second antennae, which
are parthenogenetic. Some mussel species males have never been found. project from a small notch in the front end
Mussel shrimps, also known as seed shrimps emit light to attract mates, and Their eggs are resistant to drying. of their carapace valves.
shrimps, are small, gray, brown, or the males of some even synchronize
greenish crustaceans that can measure their flashing. Eggs are released into
less than 1⁄32 in (1 mm) to just over 11⁄4 in water or stuck to plants; they may be
(3 cm) in length. They make up 61 very tough and resistant to drying.
families in 6 orders. Their indistinctly Mussel shrimps are very important
segmented body is fully enclosed in in aquatic food chains and are found
a hinged carapace, which can be worldwide, from shallow to very deep
variously shaped: circular, oval, or water, as crawlers, burrowers, or free
rectangular-oval. Its surface may be swimmers. They may scavenge, or feed
smooth or sculptured depending upon on detritus or particles suspended in the
the species. Mussel shrimps resemble water; some are predatory. There are
bivalves (see p.595) in having a carapace more than 10,000 ostracod fossil
with 2 halves, strengthened by calcium species, and they are important in oil
carbonate, that can be closed by a prospecting since different types of
muscle. The head is the largest part fossils indicate different rock strata.

I N V E R T E B R AT E S Class Maxillopoda combined mass exceeds billions Barnacles are entirely marine some backward-
of tons, and they are a major source crustaceans—they may be stalkless, pointing spines
Maxillopods of food for fishes. They are also found stalked, or parasitic. They have a shell
in freshwater, from mountain lakes made up of calcareous plates that rear-pointing
Occurrence 18,000 spp. worldwide; in oceans to hot springs. Usually under 3⁄16 in surround the body, and 6 pairs of proboscis
(sediments to deep-sea trenches), freshwater, (5 mm) in length, some parasitic species thoracic appendages. Most species
hot springs, on land may grow up to 4 in (10 cm). Generally are hermaphrodite but some are
pale, they have no carapace and lack dioecious, with sexes separated in
Copepods (Copepoda) and barnacles compound eyes. The head is fused with individuals. Barnacles may grow in
(Cirripedia) form the most significant the trunk, and the first pair of thoracic such numbers on the underside of
subclasses of this large and diverse appendages is used for feeding, while a ship, that they reduce its speed
group of 25 orders and about 310 the rest help in swimming. Fertilization by about one third.
families. Copepods are abundant is external; the male simply attaches a
everywhere in sperm packet to the female’s genitals.
the ocean—their

short
antennae

reduced suckers
abdomen
FISH LICE
2 tails used long, branched enlarged Belonging to the subclass Branchiura, members of the
as rudders first antennae head family Argulidae are commonly called fish lice; their
crab host CYCLOPOID COPEPODS CALIGID COPEPODS mouthparts are modified for sucking, enabling these
These copepods (family Cyclopidae) grasp prey with Members of the family Caligidae are ectoparasites on parasites to feed on marine or freshwater fishes. A fish
mouthparts called maxillae, and rip off small pieces using the bodies of marine and freshwater fishes. They have infested by them may get fungal infections or even
their mandibles. Some species live for more than 9 months. an enlarged head, with modified appendages to grip die. Fish lice have a cephalothorax (the head fused
A female may produce more than 10 pairs of egg sacs the host, and a reduced abdominal region. Some are with the first thoracic segment), a 3-segmented thorax,
in a lifetime, each containing up to 50 eggs. Shown red due to the presence of hemoglobin in their body. and a 2-lobed abdomen. The species shown above
above is a member of the freshwater genus Cyclops. Caligus rapax (shown here) pierces and sucks blood belongs to Argulus, the largest genus in the family.
from the skin or gills of the host.
pink brood sac, 4 – 6 overlapping,
or “externa” roughly calcareous plates
conical surround body
shell

SACCULINIDS COMMON GOOSE BARNACLES COMMON ACORN BARNACLES
The pink swelling on the underside of this crab is part of Goose barnacles (family Lepadidae) inhabit surface waters from Members of the family Archaeobalanidae can be up to 4in
a sacculinid (family Sacculinidae)—a parasitic cirripede. Adults polar to tropical oceans. The body has 2 parts: the flexible stalk (10cm) in width and height, although most are much smaller. They
have highly branched bodies that spread through the tissues of and the main body. The larvae are free swimming but adults attach encrust surfaces in large numbers and filter passing food particles.
their hosts, absorbing nutrients. Some, including the species of themselves to algae, floating wood, turtles, and ships. The largest Semibalanus balanoides (pictured) withstands freezing in Arctic tidal
Sacculina pictured, can infest half the host population in an area. barnacle, Lepas anatifera, shown here, is up to 32 in (80 cm) long. zones, and can survive out of water for up to 9 hours in summer.

CRUSTACEANS 581

Class Malacostraca abdomen. They often have stalked MANTIS SHRIMPS
Mantis shrimps (family Squillidae)
Malacostracans eyes, and their antennae are prominent. use a unique spearing (sometimes
The thorax is made up of 8 segments, smashing) technique to catch prey.
Occurrence 38,000 spp. worldwide; in marine intertidal while the abdomen has 6 segments The second pair of thoracic legs
to abyssal zones, freshwater, terrestrial habitats and a flattened tail fan (telson) that is large and specially designed for
can be moved rapidly in order to propel spearing, and is capable of striking
The world’s largest arthropod, the the animal away from predators. In very fast indeed. Mantis shrimps
Japanese spider crab (Macrocheira many species, the first 1 – 3 thoracic have a flattened, flexible body and
kaempferi) belongs to this large and appendages have become modified into stalked, compound eyes. Squilla
diverse group of crustaceans, which
comprises 18 orders and 606 families. maxillipeds, which are used in feeding; species, such as the one pictured
It has a legspan of 13 ft (4 m)—in marked right, inhabit tropical and subtropical
contrast to some other malacostracans, the remaining are used for locomotion. seas, and are territorial.
which are less than 1⁄32 in (1 mm) long. The abdominal appendages help in
Despite this vast difference in size,
malacostracans have many features swimming, burrowing, mating, and egg luminous
in common. They are often brightly brooding. Most species belong to the organs
colored, and have tough exoskeletons
strengthened with calcium carbonate. order Decapoda, which contains KRILL
Their carapace—if present—acts as Krill (family Euphausiidae) are slender,
a gill chamber, and never covers the all the familiar shrimps, crayfish, crabs, eyes shrimplike crustaceans that filter food
and lobsters. They often have an particles from sea water using the long
hairs on their thoracic legs. They are
enlarged first pair of appendages highly gregarious, and also luminescent.
The species shown left, Antarctic krill
equipped with claws. Important (Euphausia superba), forms very large
swarms that sometimes have a collective
in the marine food chain, many weight of more than 2 million tons. In the
Arctic Ocean, these swarms are an
of the bigger species are of important food for baleen whales.
spinelike rostrum
commercial value. thoracic legs SHRIMPS
Pigment cells (chromatophores) present
long PRAWNS soft, transparent well-developed, in their body allow these bottom-dwelling
antennae Members of the family Palaemonidae have body compound eyes omnivores (family Crangonidae) to change
a carapace that extends forward to form a first 2 pairs of color. The carapace is extended to form
upturned rostrum, which may have toothed edges. Most walking legs a short spinelike, smooth-edged rostrum.
rostrum species are colorless and transparent. They use have claws The common shrimp, Crangon crangon
their claws to pick up food. The common prawn, (pictured left), is fished commercially
long along European coastlines. I N V E R T E B R AT E S
Palaemon serratus (shown left), has very long antennae
antennae, up to 1.5 times longer than CANCRID CRABS
the body, that warn it of the presence of When adult, cancrid crabs (family
predators. This species is caught in Cancridae) typically live on the
huge numbers since it is a seabed, where they prey on other
common human food.
invertebrates and scavenge for
transparent body tail fan dark claw tips dead remains. The species
shown here is the European
BURROWING SHRIMPS toothed oval edible crab, Cancer pagurus,
These shrimps (family edge carapace which has a distinctive “pie
Callianassidae) make U- or large, brightly crust” edge to its carapace.
notches on Y-shaped, or branched, networks colored claw
lateral border of burrows in silt and mud in Found off the European
of carapace shallow water. They are soft- Atlantic, Mediterranean,
bodied crustaceans, predatory and West African coasts,
on small organisms and worms. it is up to 12 in (30 cm) across.
These shrimps are collected as It is commercially fished in many
fish bait in some parts of the areas and large specimens
world. The picture on the left are now rare.
shows a species from the genus long-stalked
Callianassa. In this genus, one of eyes
the first thoracic legs may be
wide, flattened much larger than the other.
carapace SWIMMING CRABS
Swimming crabs have paddlelike hindlegs
that help them to swim efficiently. As in
other crabs, the short abdomen is folded
like a tail under the body. The common
shore crab, Carcinus maenas (pictured),
buries itself in mudflats and sandy
regions. Known as the green crab in North
America, this species is not as good a
swimmer as other members of the
family Portunidae.

GHOST AND FIDDLER CRABS
In the tropics, ghost and fiddler crabs (family Ocypodidae) abound on low-lying coasts. Ghost crabs
live in burrows on sandy beaches, and emerge after dark, feeding on debris washed up by the tide.
They have keen eyesight, and are extremely rapid runners, disappearing into their burrows at the first
hint of danger. Fiddler crabs, which are smaller, burrow into the mud of mangrove swamps. Males
have one large claw, which they wave to attract females and to deter rivals. The claw often makes
up half the male’s weight. Fiddler crabs feed on organic matter present in silt. There are about 97
species; shown here is the male orange fiddler crab, Uca vocans, from Africa and Southeast Asia.

I N V E R T E B R AT E S 582

CRUSTACEANS 583

Class Malacostraca species the alternative names of
decorating or masking crabs. Spider
Superfamily Majoidae crabs range from small species with a
carapace length of around 5⁄16 in (8 mm) to
Spider crabs and the massive Japanese spider crab—also
relatives known as the giant spider crab—which
has a carapace up to 20 in (50 cm) long
Occurrence c.1,000 spp. in all but polar oceans (see below).
and seas; from the intertidal zone to waters 6,500 ft
(2,000 m) deep

Spider crabs are recognized by their GIANT AMONG ARTHROPODS
triangular carapace, a shape formed by The Japanese spider crab, Macrocheira
a narrowing of the front edge, which is kaempferi, is the world’s biggest living
often extended as an elongated rostrum. arthropod. Its legs may be up to 5 ft (1.5m) long.
As the common name implies, many
species have long, slender legs. In most pointed fine, yellow
cases, the pincer-bearing legs (chelipeds) rostrum lines
are not much longer than the other legs.
Spider crabs use their chelipeds to attach long, slender
sponges, seaweed, hydroids, and even legs
detritus, such as wood fragments and
broken worm tubes, to hooked hairs round violet- I N V E R T E B R AT E S
on their carapace and legs. In some eyes tipped
species, the entire body can be covered, claws
making the crab very difficult to see
and protecting it from predators.
If forced to move to a different
location, some will change
their camouflage to match
their new surroundings. This
behavior has given these

YELLOWLINE ARROW CRAB
Yellow lines on the carapace, running backward
from the eyes, and the arrow-shaped rostrum

give this species, Stenorhynchus seticornis,
its common name.

DIMINUTIVE FORM
The dainty yellowline arrow crab—at most, 21⁄2 in
(6.5 cm) long—is found in the Atlantic Ocean from
the Caribbean to as far south as Brazil. Males can
tell how close a female is to laying eggs and, after
they have mated, will guard the female from the
attentions of other males.

584 ARTHROPODS

Class Malacostraca continued

bright red body gastropod large claw blocks
with blue spots shell entrance to shell
and lines when crab retreats
transverse into it
markings on body
rough,
short granular
spines surface
of claws
LAND HERMIT CRABS
Like hermit crabs, land hermit crabs (family Coenobitidae) also
carry shells around. An exception is the coconut or robber crab,
Birgus latro, pictured fighting above, which does not have a shell. It is
the heaviest terrestrial crustacean, with a weight of up to 83⁄4 lb (4 kg).
It lives in the tropics, and feeds mainly on the fruit of coconut palms.
A good climber, its slow speed means it is easy to hunt and is
becoming rare in some places.

SQUAT LOBSTERS HERMIT CRABS
Squat lobsters (superfamily Galatheoidae) are relatively The most characteristic feature of hermit crabs (superfamily
slow movers but most species use their abdomen to swim Paguroidea) is that they carry the shells of gastropods around
rapidly backward to escape predators. Many species are as homes, changing an old shell for a bigger one as they
mainly nocturnal and hide under rocks and in cracks grow. The white-spotted hermit crab, Dardanus megistos,
during the day. Shown here is the blue-striped squat shown above, inhabits the lower shores of sandy and rocky,
lobster, Galathea strigosa, from European shallow seas. Northern and Western European coasts.

I N V E R T E B R AT E S blue upper
body

spiny CRAYFISH
rostrum Members of the family Astacidae, freshwater crayfish resemble small
lobsters. The first 3 pairs of legs have claws, the front pair being the
largest. They make burrows in silt or mud where they hide during the
day. The white-clawed crayfish, Austropotamobius pallipes, shown
above, inhabits well-aerated streams in southwest Europe.

pill woodlouse
rolled into a ball

oval body
short
antennae

LOBSTERS segmented ONISCID WOODLICE PILL WOODLICE
The family Nephropidae includes the largest and most brownish Most oniscid woodlice (family Oniscidae) Pill woodlice or pillbugs (family Armadillidiidae) have
commercially important crustaceans, the lobsters. body are terrestrial, living in damp microhabitats, the ability to roll into a tight ball for protection. They
Measuring up to 31⁄4 ft (1 m) in length, lobsters have a such as rotting wood, under stones, and have a rounded back as well as a rounded hind margin.
roughly cylindrical carapace with transverse and oblique in caves. They have a flattened body with Usually terrestrial, they have 2 pairs of lunglike organs
grooves. The abdomen is elongated with a broad tail fan clear segmentation and no carapace. (pseudotracheae) on the abdominal appendages for
for rapid backward escape. The common lobster, Homarus Females have a brood pouch formed from plates breathing air. As in many woodlice, the newly hatched
gammarus, shown above, has a blue upper and a at the bases of the first five pairs of walking legs, or young have one pair of legs fewer than they will have
yellowish lower surface. Using its large claws, it pereopods. The common shiny woodlouse, Oniscus as adults. Pictured here is the common pill woodlouse,
cracks open mollusks and feeds on them at night. asellus, pictured left, has a shiny, mottled grayish Armadillidium vulgare.
body with 2 rows of pale patches.
long first
antennae

OPOSSUM SHRIMPS SKELETON SHRIMPS swimming
Shrimps of the family Mysidae, Skeleton shrimps (family Caprellidae) appendages
have distinctive movement sensors do not swim, and instead cling to BEACH-HOPPERS
at the base of the inner pair of seaweed, catching food that drifts within Beach-hoppers and their
flaplike appendages on either side reach. Their bodies are extremely slender, relatives (family Gammaridae)
of the tail fan. Most of them live with a long thorax and a tiny abdomen. The live on the coast and in freshwater,
worldwide in estuarine or marine specimen shown here belongs to the genus often among rotting vegetation. Most
waters (from the coast to the deep Caprella, which, with over 140 species, is the species—like this one from Europe—have
sea), and are free swimmers. largest in the family. Close relatives of these a curved abdomen that can flick the animal
Elongated and soft bodied, many animals live on whales and dolphins. away from danger.
are pale or translucent but deep-
sea species are red. Many form
schools and are important food
for both fishes and humans.

HORSESHOE CRABS 585

Sea-spiders Family Nymphonidae

PHYLUM Arthropoda Sea-spiders are unusual marine arthropods Feeding Nymphonid sea-
SUBPHYLUM Chelicerata with a small, cylindrical body and long, slender spiders
legs that give them a superficial resemblance Most sea-spiders are carnivores,
CLASS Pycnogonida to terrestrial spiders. They occur throughout feeding on soft-bodied marine Occurrence 268 spp. in the coastal Atlantic region;
animals such as sponges, in intertidal to shallow water
anemones, corals, hydroids, and
ORDERS 1 (Pantopoda) the world’s oceans, occupying habitats lace corals. When feeding, they
usually straddle their prey and either
FAMILIES 13 ranging from shallow, coastal areas to deep suck its tissues up through their
proboscis or break off small pieces
SPECIES About 1,330 ocean waters. Most live on the sea bottom, from its body with their chelicerae Slender bodied, and with a stout
and then pass them to their mouth. proboscis, nymphonids are more active
although some can swim. The greatest and swim around more than other
sea-spiders. They measure 1⁄32 – 5⁄16 in
numbers of species and the largest individuals—with legspans (1–8 mm) in length. The chelifers—a pair
of up to 30 in (75 cm)—are found in deep water. of appendages at the front—are typically
clawed. Both males and females have
Anatomy egg-carrying legs that have 10 segments
and may carry masses of up to 1,000
Sea-spiders have a small head, or cephalon, 3 eggs. There may be 4 – 6 pairs of normal
trunk segments, and a short abdomen. The head walking legs. These sea-spiders eat
has a raised projection that supports 2 pairs of soft-bodied invertebrates such as
eyes. It has a proboscis used for feeding, 2 hydroids and bryozoans. Most species
clawed appendages (chelifers) and a second inhabit deep water, although some are
pair known as palps. Most sea spiders have found in shallow, coastal water.
4 pairs of walking legs arising from the trunk
segments but some have 5 or 6 pairs. Most long walking legs thin carapace
sea-spiders have 4 pairs of walking legs
arising from the trunk segments, but some I N V E R T E B R AT E S
have 5 or 6 pairs. The front pair is used
for carrying eggs and grooming. Sea-
spiders have no respiratory or digestive
organs: gases and dissolved substances
are absorbed and released by diffusion.

STRADDLING PREY NYMPHON SP.
These smooth-bodied animals are often
This yellow-kneed sea-spider is feeding on a overlooked because they are so small. Their legs
colony of hydroid polyps. It keeps its legs in one may be 3 or 4 times longer than their body.
position while moving its body over the polyps.

Horseshoe crabs Family Limulidae

PHYLUM Arthropoda Also known as king crabs, these are Feeding Horseshoe crabs
SUBPHYLUM Chelicerata the only living representatives of a once
diverse and successful group of animals Horseshoe crabs are scavengers, Occurrence 4 spp., 1 in North America, 3 in Southeast
CLASS Merostomata that flourished over 300 million years ago. burrowing through sediment and mud Asia; on the seabed
in search of food such as mollusks,
ORDERS 1 (Xiphosura) Although they are called crabs, they are not worms, and other marine animals. The 4 living species of horseshoe
They catch prey using their chelicerae crabs all belong to the family Limulidae.
FAMILIES 1 (Limulidae) crustaceans, but close relatives of arachnids. or their first 4 pairs of walking legs, They get their name from the horseshoe-
and then transfer it to the mouth. shaped shield, or carapace, that covers
SPECIES 4 They live in shallow waters off the coasts all of the body except the tail. Colored
a drab brown, horseshoe crabs are up
of North America and Southeast Asia, and to 231⁄2 in (60 cm) long. The abdomen
is hinged to the cephalothorax and
are most evident in spring, when they emerge from has leaflike gills on the underside;
the tail spine, at the rear, is used to
the sea to mate and lay their eggs. right themselves when overturned.
Components of their blue blood have
Anatomy been used in medical research.

Horseshoe crabs have a fused
head and thorax, jointly called the
cephalothorax. This is covered by
a tough, horseshoe-shaped shell,
or carapace, and supports 7 pairs
of appendages: one pair of chelicerae,
one pair of palps, 4 pairs of walking
legs and a chilarium. The abdomen
bears a long, spinelike tail and 5
pairs of leaflike gills. Horseshoe
crabs have a pair of simple eyes at
the front and a pair of compound
eyes on either side.

REPRODUCTION LIMULUS POLYPHEMUS
The Atlantic horseshoe crab is not yet an
Every spring, horseshoe crabs gather along endangered species but is thought to be
the Atlantic shoreline of the USA to mate. declining in numbers due to exploitation, habitat
Eggs are deposited in the sand and then loss, and disturbance of egg-laying sites. Its
fertilized by the males. eggs are a major food for many seabirds.

586 ARACHNIDS

Arachnids

PHYLUM Arthropoda This diverse group includes the familiar or have a tail-like extension. It houses Some spiders rely on sight and stealth
SUBPHYLUM Crustacea spiders, scorpions, and harvestmen. the respiratory organs: gases are to catch their prey. Others use silk to
However, by far the most common and exchanged via the trachea or organs build traps. For example, some spiders
CLASS Arachnida widespread members of the group are the known as book lungs. In spiders, the build spirals of sticky silk, called orb
ORDERS 12 ticks and mites. All arachnids have 2 main abdomen also contains silk glands. webs; those of some tropical species
FAMILIES 661 body segments and 4 pairs of legs (unlike are large and strong enough to entrap
SPECIES 103,000 insects, which have 3 main segments and Feeding small birds. Net-casting spiders make
small webs, which they hold in their
3 pairs of legs). Most are terrestrial animals, Most arachnids are predacious, legs and drop over passing prey.
but a few are scavengers and some
although about 10 percent of ticks and mites (and one species mites are parasitic. Large arachnids Reproduction
usually rely on strength to subdue
of spider) are found in freshwater. their prey but spiders, scorpions, In most arachnids, the male passes a
and pseudoscorpions can also inject packet of sperm (or spermatophore)
Anatomy second pair, called the pedipalps, are venom. Since arachnids have narrow to the female using his pedipalps,
leglike or enlarged with claws at the mouths, they cannot ingest large chelicerae, or legs. The female
An arachnid’s body is divided into 2 end. The other 4 pairs are walking pieces of food. They usually release releases the eggs, which in some
sections. The head and thorax are legs, although in some species, the digestive enzymes over the prey scorpions hatch immediately. In
fused to form a cephalothorax, which first pair are long and have a mainly and then suck up the resulting liquid. some species, the young develop or
is joined to the abdomen, in some sensory function. In scorpions, small pieces of prey are hatch inside the female’s body. Many
species by a narrow stalk. partly digested in a small chamber in arachnids show parental care by
The abdomen front of the mouth. guarding their eggs.
The cephalothorax bears 6 pairs may be divided
of appendages. The first pair, known into smaller
as the chelicerae, are pincer- or fang- segments,
like and used mainly for feeding. The

I N V E R T E B R AT E S

HUNTING

Like most arachnids, this wolf spider eats live prey. It has
impaled this grasshopper with its chelicerae, which each
end in a hinged fang. The adjacent pedipalps are being
used to manipulate the prey. Wolf spiders have acute
vision and usually hunt at night.

ARACHNIDS 587

Order Scorpiones Family Scorpionidae for some time after their first molt.
Scorpionids have a 5-sided sternum in
Scorpions Scorpionids contrast to the buthids’ triangular one.

The most ancient group of all arachnids, scorpions are recognizable Occurrence 196 spp. in Africa, Asia, and Australia; PARDINUS IMPERATOR
by their large, clawlike pedipalps, and their sting-bearing tails. They in cracks, caves, under stones, logs This is the emperor scorpion, some specimens
hunt after dark, often finding prey by touch. Scorpions sometimes use of which can exceed 21⁄8 oz (60 g) in weight.
their stings to paralyze prey, but the sting’s key function is defense. This family includes the world’s It can be found among leaf litter in
Females give birth to live young, which they carry on their backs. largest scorpions, measuring the tropical forests of Central
There are about 1,500 species in 15 families. up to 81⁄2 in (21 cm) long. Although and West Africa.

Family Buthidae large tail long, clawlike they look menacing, the larger species large
sting pedipalps tend to be less venomous than the pedipalps
Buthids smaller ones and rely primarily on
physical strength to overpower their
Occurrence c.650 spp. worldwide, in warmer regions; prey. Many of these dig to locate
in rock cracks, under stones, logs, bark prey, which could include spiders,
lizards, and even small mammals.
Despite their relatively small size, spurs Scorpionids sting not only to chelicerae eyes
31⁄4 – 43⁄4 in (8 – 12 cm) in length, buthids on tibiae paralyze their victim, but may
are the most dangerous scorpions. BUTHUS OCCITANUS also sting mates as part of their
Their potent venom can paralyze the An inhabitant of scrubby ground, the common complex mating ritual. A litter of
heart and the respiratory system. yellow scorpion occurs in parts of North Africa and 30 – 35 young stay with the mother
West Asia. Antidotes to its venom are available.

Order Pseudoscorpiones Order Solifugae I N V E R T E B R AT E S

Pseudoscorpions Sun-spiders or wind-scorpions

Also called false scorpions because they lack a sting and tail, Neither true spiders nor scorpions, the animals in this order lack
members of this order of 25 families (about 3,300 species) are similar poison glands. Instead, they kill and chew up their prey with their very
to scorpions in shape. They have venom glands in pincerlike parts large, pincerlike chelicerae. Their leglike pedipalps have suction pads
in their pedipalps and prepare silk nests in which to molt, brood their that hold down the prey so that it can be eaten. There are about 1,100
young, and hibernate. Eggs are laid in a special brood pouch. Females species, in 12 families, and most are found either in North America or
may cling to other animals to disperse to new habitats. in the tropics.

Family Neobisiidae Family Cheliferidae Family Solpugidae 20 – 100 eggs. Some solpugids are
active by day; others burrow in sandy
Neobisiids Cheliferids Solpugids soil or hide in cracks, or under stones
during the day, and forage in tree
Occurrence c.500 spp. worldwide, especially in the Occurrence c.300 spp. worldwide, especially in warmer Occurrence 190 spp. in Africa, parts of West Asia; on canopies at night.
Northern Hemisphere; in leaf litter, soil, caves regions; in leaf litter, on tree bark ground, under stones, logs, in burrows in sandy soil

Habitat Terrestrial

The members of this family are very Unlike in neobisiids, in cheliferids both Pale, brown or yellowish, sometimes
fingers of the pincers have glands that with bright markings, these sun-spiders
small, measuring 1⁄32 – 3⁄16 in (1 – 5 mm) produce the venom they use to paralyze are 1⁄4 – 21⁄4 in (0.6 – 6 cm) in length. Their
their prey. There are no teeth on the inner 4 pairs of legs have a variable number
in length. They usually have 4 eyes but surfaces of the pincers. Cheliferids are of tarsi and all, except the first pair,
3⁄64 – 3⁄16 in (1.5 – 5 mm) long and usually have claws with a smooth surface.
cave-living species may have fewer have 2 eyes. Coloration varies from pale They have forward-facing chelicerae
to dark brown or black, often tinged with to kill prey; small species and nymphs
eyes or none at all. In color, neobisiids red or olive, with dark markings. As in eat termites. Females lay masses of
many arachnids, courtship can be
vary from olive- to dark brown, with red, complex; males and females dance Family Ammotrechidae METASOLPULGA PICTA
holding each other’s pedipalps. This species is found in the Namib Desert in
yellow, or cream tinges. The legs are Ammotrechids Namibia. Like all solpugids, it will bite if handled
pedipalp carelessly, but does not have venom glands.
often slightly green, with 2-segmented Occurrence 83 spp. in the warmer regions of South,
Central, and North America; in rotten tree stumps or inside the tunnels of wood-boring
tarsi. The claw of each pedipalp has insects. These arachnids are predatory
on a range of arthropods. Females may
one venom gland located in the fixed lay 2 or more masses of 20 – 150 eggs
in their lifetime.
finger; after paralyzing its prey, the

neobisiid shreds it with its

large mouthparts. red-brown
pedipalps

NEOBISIUM MARITIMUM brown This family comprises relatively slender AMMOTRECHELLA STIMPSONI
Measuring 1⁄8 – 9⁄64 in (3 – 3.5 mm) long, the coloration species that measure 5⁄32 – 3⁄4 in This species is found in Florida and other areas
maritime pseudoscorpion is found in cracks DACTYLOCHELIFER SP. (0.4 – 2 cm) in length. They are colored in southern North America, where it lives in the
in rocks and under stones in coastal areas While most of these species are distributed in shades of brown. The front margin bark of rotten, termite-infested trees.
of Ireland, England, and France. across the Northern Hemisphere in a variety of of the head is rounded, and the tarsi of
habitats, some are confined to coastal habitats. the first pair of legs do not have claws.
Many species are nocturnal and dig
into the soil during the day. Some of
the smaller ones hide in termite galleries

588 ARTHROPODS

Order Uropygi Order Opiliones

Whip-scorpions Harvestmen

These flat-bodied arachnids have a whiplike tail (telson) at the end of Harvestmen—or daddy longlegs—are often mistaken for spiders,
their abdomen and can, in defense, squirt formic and acetic acids from but they have rounded bodies, without a slender waist. Their legs are
a pair of abdominal glands. Their chelicerae resemble spider fangs. long and slender, and end in microscopic claws. Their mouthparts
There is 1 family, with 106 species. are small but they produce noxious secretions as a defense.
Harvestmen are unusual among arachnids in that fertilization
Family Thelyphonidae acid over 231⁄2 in (60 cm), and can give is direct. There are at least 6,125 species, in 48 families.
a painful pinch with their pedipalps.
Vinegaroons Excluding the tail, they are up to Family Cosmetidae Family Phalangiidae
3 in (7.5 cm) long.
Occurrence 100 spp. in North America and N.E. South Cosmetids Phalangiids
America; in leaf litter, under stones, rotten wood THELYPHONUS SPP. strong pedipalps
Dark brown, with a tough, for digging Occurrence 700 spp. mainly in tropical regions of North Occurrence 380 spp. worldwide; under stones, among
Vinegaroons hunt after dark, hiding in flattened body, these burrows and South America; under stones, among debris leaf litter in woods, grassy areas
underground burrows during the day. arachnids are found in
They do not have a sting but can squirt Southeast Asia.

segmented Like most harvestmen, cosmetids Phalangiids can have a legspan of up
telson to 4 in (10 cm), but their soft bodies are
are generally dull in color, although rarely more than 3⁄8 in (1 cm) long. Like
other harvestmen, their eyes are close
tropical species can be green or yellow, together, and are on a “turret” above
the rest of the body. Males and females
Order Amblypygi and a few can change color over a differ; the enlarged chelicerae of the
males are especially distinct. Females
Whip-spiders matter of weeks to blend with their lay 20 – 100 eggs at a time, burying
them in soil or under bark. Most species
Also known as tailless whip-scorpions, members of the 5 families surroundings. They range from are nocturnal and prefer humid habitats.
(about 160 species) in this order do not sting or bite. They are Phalangiids are both predatory
nocturnal and cave dwelling, with fanglike, segmented chelicerae, 3⁄16 – 3⁄8 in (5 – 11 mm) in length. Males and saprophagous.
large, shiny pedipalps, and an extremely long first pair of legs.
tend to be smaller than females but long second pair
Family Phrynidae of legs
have longer appendages and larger
Phrynids
chelicerae. The eyes are located close

I N V E R T E B R AT E S together on a small “turret” called an

ocularium. Females use their ovipositors

to lay eggs in cracks and crevices

in the soil. small pedipalps,
close to
chelicerae

Occurrence 60 spp. in tropical and subtropical regions;
under stones, bark, in leaf litter and caves, among rocks

Brown, with dark markings, phrynids PHRYNUS SPP. VONONES SAYI long, PHALANGIUM OPILIO
have a body 3⁄16 – 21⁄4 in (0.5 – 6 cm) This phrynid, from Central America, has bent its The Say’s harvestman slender Found in the Northern Hemisphere, the diurnal
long. They scuttle rapidly sideways long front legs backward—a typical resting pose. is found in Panama. It legs horned harvestman likes sunny spots, and
if disturbed. Females carry young for uses its front legs to inhabits woods, gardens, and grassland.
months in a sac under the abdomen. smear toxic secretions
on attackers.

Order Acari Family Trombidiidae start life as parasites, attacking insects,
spiders, and harvestmen. The adults
Ticks and mites Velvet mites often emerge from the soil after rain
to mate and lay eggs.
With over 48,200 species and about 438 families, ticks and mites Occurrence 300 spp. worldwide, especially in tropical
are present in almost every habitat, particularly on land. They include regions; in or on soil, some associated with freshwater TROMBIDIUM SPP.
many pests of crops and stored food, as well as parasites that attack Trombidium velvet
mammals, birds, and reptiles. Most are less than 1⁄32 in (1 mm) long— Named after their dense, velvety “fur,” mites are found in
although ticks can grow much bigger after feeding on blood—and these bright red or orange mites eat many parts of the
unlike spiders, their bodies have no distinct divisions. insect eggs when they are adult, but world. This species,
from South Africa,
Family Ixodidae (0.2 – 1 cm) long but grow larger after Family Tetranychidae grows up to 3⁄8 in
feeding. Colors vary from yellow to red (1cm) long.
Hard ticks or black-brown; some species are highly Spider mites
marked. Some hard ticks carry viral produce silk. Eggs are laid on leaves,
Occurrence 700 spp. worldwide; in association with diseases that affect humans, including Occurrence 700 spp. worldwide; on a range of trees, and the young are protected by silk
birds, mammals, and some reptiles encephalitis and Lyme disease, as well plants, and shrubs webs. They suck sap and heavy
as diseases affecting cattle and poultry. infestations can weaken a plant.
Hard ticks have a tough dorsal plate, Habitat All
which fully covers the males, but covers mouthparts AMBLYOMMA TETRANYCHUS SPP.
only the front half in females. The AMERICANUM These soft-bodied mites are orange, Abundant in
abdomen is soft and flexible to allow for pitted The lone star red, or yellow, and ⁄1 128 – 1⁄32 in temperate regions,
large blood meals. The front part of their surface tick is common in (0.2 – 0.8 mm) long. Many species red spider mites
head projects forward and carries the may produce 4 – 5
mouthparts. Hard ticks are 1⁄16 – 3⁄8 in the grassland of generations per year.
Central America. They are pests of
deciduous fruit trees.
4 similar
pairs of legs

ARACHNIDS 589

Order Araneae Family Agelenidae long,
hairy legs
Spiders Funnel weavers
femur darker patterned
Spiders can be distinguished from other arachnids by their Occurrence 1,150 spp. worldwide; in meadows, than rest cephalothorax
distinctive appearance and by their ability to produce silk. A typical gardens, bushes, houses, among stones, on walls of leg
spider has 8 eyes, and a body divided into 2 parts—the cephalothorax
and the abdomen. The mouth is flanked by a pair of venom-injecting Funnel weavers are often long-legged, distinctive
fangs, and a pair of leglike pedipalps. These have a sensory function and have minute, feathery hairs on the patterning on
and, in males, are also used to transfer sperm. All spiders are body, 8 eyes, and a slender abdomen abdomen
predatory, injecting venom into their prey. Some use silk to catch with dark bars, chevrons, or spots.
prey, but spiders also use silk to protect their eggs, lower themselves The body is 1⁄4 – 3⁄4 in (0.6 – 2 cm) long. TEGENARIA DUELLICA
through the air, and even to sail on the breeze. There are over 42,000 The funnel weaver’s web takes the form This giant house spider can have a legspan
species, in about 110 families, and they live in every terrestrial habitat, of a flat, tangled silk sheet with a tunnel of up to 31⁄4 in (8 cm), and can run very fast.
from tropical rain forests to cellars and caves. on one side. Females may feed their Members of the genus Tegenaria are called
offspring by regurgitation and, in some house spiders. The large spiders that fall into
Family Araneidae to snare moths. The strength of the species, the spiderlings may eat the domestic baths usually belong to this genus.
webs can be such that in Papua New mother when she dies.
Orb web spiders Guinea, the huge webs of the Nephila ARGYRONETA AQUATICA I N V E R T E B R AT E S
species are used as fishing nets. Orb Family Cybaeidae This spider lives permanently in still or
Occurrence c.3,100 spp. worldwide; in grassland, web spiders often have very large, slow-moving water, and the air trapped by
meadows, woodland, forests, gardens brightly colored, and patterned Cybaeid spiders the body hairs around the abdomen gives
abdomens; in tropical species, the it a silvery appearance.
Habitat Terrestrial abdomen may have unusual, angular Occurrence 180 species in North America, South
shapes. The legs have 3 claws that America, and Eurasia
As the name implies, many of these can be very spiny. Of the 8 eyes, the 4
spiders weave circular webs made up in the middle often form a square. Orb Over 100 species of Cybaeus make webs
of a central hub with radiating lines and web spiders are 1⁄16 – 13⁄4 in (0.2 – 4.6 cm) in stone crevices or under logs, but this
spirals of sticky and nonsticky silk. They long. Males approach females on their family’s best known member is the water
typically catch prey in the web, wrap it webs and pluck threads to attract them. spider (Argyroneta): the only spider that
in silk, cut it out, and take it to a retreat Females lay eggs in silk cocoons that lives under water. It ferries air, trapped
to eat it. Some species spin opaque can be camouflaged in webs and litter, by its dense abdominal hair, to a silken
bands of matted silk in their webs so or stuck to vegetation or bark. “diving bell” anchored to pond weed.
that birds can see them and do not The bell is used for feeding, courtship,
accidentally destroy the webs by falling banded hibernation, and stowing eggs.
into them. However, there are a few legs
species that do not make webs; these
prey after dark, using a single thread cross-
with a bead of glue at the end shaped
abdominal
markings

Family Hexathelidae Family Linyphiidae

Funnel-web spiders Dwarf spiders

Occurrence 180 spp. in tropical regions of the Americas, Occurrence 4,400 spp. mostly in temperate regions of
Africa, Asia, and Australia; in trees, on ground the north, some in Arctic; on stones, among vegetation

bright colors
deter birds

stout abdominal ARANEUS DIADEMATUS Funnel-web spiders belong to a group Also known as money spiders, these tiny
projections Variably colored (from pale known as mygalomorphs, which also animals are rarely more than 3⁄8 in (1 cm)
reddish to almost black), the long. They have large chelicerae with
GASTERACANTHA European garden spider, or includes tarantulas (see p.593). Unlike sharp teeth. The legs have strong bristles
CANCRIFORMIS garden cross spider, inhabits woods other spiders, mygalomorphs are and the carapace of males may have
These tough-bodied, spiny-bellied and gardens in Europe and North relatively primitive, with fangs that extensions, which sometimes carry the
orb weavers are found in North America. Its webs can be nearly strike downward, instead of closing eyes. Dwarf spiders live in leaf litter or
and South America. They are 20 in (50 cm) across. sideways like a pair of pincers. make characteristic, horizontal,
often seen hanging in the middle Funnel-webs are 3⁄8 – 11⁄4 in (1 – 3 cm) nonsticky, sheetlike webs
of their webs. They inhabit shrubs mottled long and, usually, dark brown. Most among vegetation. Egg sacs
and trees, and their webs can camouflage make a funnel-shaped retreat that leads are attached to stones, plants,
also be seen on walls of houses. coloring into crevices in tree stumps or rocks. and other surfaces. These
Some are highly venomous. spiders travel over long
MICRATHENA GRACILIS distances by “ballooning”
Called the spined micrathena spider, spinelike on long, silk threads.
this species inhabits woodland and projections
forests in North America. on abdomen

dark bright red-orange
red-brown cephalothorax
carapace
red-orange
legs gray, oval
long
spinnerets abdomen
ATRAX ROBUSTUS GONATIUM SP.
The Sydney funnel-web, a native of Southeast These small spiders are widespread in the
Australia, is an aggressive spider that has Northern Hemisphere, inhabiting scrubland
a painful, venomous bite that may prove fatal. and grassland. They prefer low, shaded bushes.

590 ARTHROPODS

Order Araneae continued STRIKING APPEARANCE BRIGHT PATTERN
Maratus bubo is one of several species of jumping
Family Salticidae Some tropical jumping spiders are very brightly spiders known as peacock spiders, which are found
colored, with iridescent hairs arranged in patches in western Australia. The bright coloration on the
Jumping spiders and spots. In some, the whole of the upper surface abdomen of the male peacock spider is structural
of the abdomen may be bright red or orange. color, and not due to pigments.
Occurrence 5,500 spp. worldwide; in grassland, Males often have enlarged front legs and
meadows, woodland, forests, gardens ornamented pedipalps, which they use to
attract the attention of females.

The 5,000 species of jumping spiders PHIDIPPUS REGIUS CHRYSILLA SPECIES
(salticids) make up one of the largest Males and females of These spiders catch and eat
of the spider families. Most jumping this species, native to
spiders have stout, hairy bodies, S.E. North America, ants in preference to any
1⁄16 – 1⁄2 in (2 – 16 mm) long, and are often communicate using more other kind of insect.
drab in appearance, although many than 20 different signals Some species jump
tropical species are vividly colored, made with their legs and on their prey from
with elaborate markings. Some species palps. Other spiders in behind, while
are very antlike, mimicking their prey the genus do the same.
in both looks and behavior. Although thickened others tackle the
the different species do vary greatly, brightly front legs ant head first.
a distinctive feature common to all is colored
their prominent eyes. At the front of the carapace
carapace, which is rectangular, with a
I N V E R T E B R AT E S rounded rear and square front, sits a distance, shape, and
row of 4 large eyes. The middle 2 eyes, movement very accurately, and
which are very much larger than the give them the most keen vision of any
others, resemble old-fashioned car spider. The back of the eye capsule
headlights. These eyes enable can be moved inside the head to keep
jumping spiders to judge the image of the prey centered on the

light and dark retina. The smaller outside
bands on legs eyes and a pair toward the
rear of the carapace simply
compact body detect movement. Jumping spiders
are active during the day, stalking insect
drab prey on the ground, on walls, and in
coloration bushes, especially in warm, sunny
locations. Their characteristic hunting
EUOPHRYS SPECIES method of jumping on their prey to
Members of the genus Euophrys seize it gives them their common name.
are often found on the ground, among grass and When the weather is bad, they retreat
low-growing plants, or under stones. As in many to a small, silken nest they make in
species, males fight for access to a female, the a crevice or crack. The spiders use
larger male usually winning. similar shelters over winter and
when they molt or lay eggs. The
eggs, laid among vegetation, bark,
and moss, are wrapped in silk,
and the female guards them until
they hatch.

JUMPING

Salticids jump not only to catch
prey but also to escape from
predators. The hind pair or 2 hind
pairs of legs are extended rapidly
by hydraulic pressure.

ATTACKING PREY BAGHEERA KIPLINGI
Before it leaps, a jumping spider attaches This jumping spider is the only known
a safety line of silk in case it gets carried herbivorous spider. In its native Central American
off course. This species is known as the forests, Bagheera kiplingi lives on acacia trees
zebra spider on account of its striped that produce nutrient-rich nodules to sustain
markings. The mouthparts (chelicerae) of colonies of ants. In turn, the ants clear the
males are larger than those of the females. acacia of leaf-eating insects. The spider feeds
from the nodules, too—but without providing
the tree with anything in return.

591 I N V E R T E B R AT E S

592 ARTHROPODS

Order Araneae continued

Family Lycosidae Family Pholcidae 1⁄8 – 1⁄2 in (3 – 14 mm) long and have Family Pisauridae
flexible tarsi, with many false joints.
Wolf spiders Daddy longlegs Also known as cellar spiders, daddy Nursery-web spiders
spiders longlegs spiders make tangled,
Occurrence 2,400 spp. worldwide, even in Arctic irregular webs and quickly wrap prey Occurrence 300 spp. worldwide; on ground, surface
regions; mostly on ground, among leaf litter Occurrence 1,000 spp. worldwide; in caves, leaf litter, in silk before biting it. When disturbed, of still water, aquatic plants
dark corners of buildings they vibrate their webs rapidly, making
Habitat All terrestrial themselves appear blurred and difficult Habitat All
to spot. Females carry 15 – 20 pale,
Wolf spiders are 5⁄32 – 11⁄2 in (0.4 – 4 cm) Pale legs that are much longer than pinkish gray eggs, held with These large spiders resemble wolf
long and have excellent eyesight, which the body give these spiders a spindly silk, in their chelicerae. spiders (see left) in appearance and
helps them in their nocturnal hunts. appearance. Colored gray, green, or hunting technique—running and
They are pale gray to dark brown, with brown, they have eyes arranged in 2 long, flexible catching prey on the ground rather than
markings such as bands, stripes, or groups of 3 each, with another pair in tarsi using webs. The carapace is oval and
spots. Females often carry their egg between; a few cave-dwelling species, has longitudinal markings; the body is
sacs attached to their spinnerets or, in however, are blind. These spiders are extremely 3⁄8 – 1 in (1 – 2.6 cm) long. The females
burrowing species, keep the sacs in a long legs carry the egg sacs in their chelicerae
silk-lined burrow. They carry spiderlings slung below the body, placing them in
on their backs. Some wolf spiders are tibiae tentlike nursery webs at hatching time.
important predators in field ecosystems. The sacs and spiderlings are guarded
This family includes the true tarantula, circular by the females until the second molt,
Lycosa tarentula, of southern Europe. cephalothorax when they leave the web and disperse.

dark “knees” elongated
conspicuous gray
palps in male abdomen

I N V E R T E B R AT E S brown body

PARDOSA AMENTATA PHOLCUS PHALANGIOIDES PHOLCUS SP. PISAURA MIRABILIS
This European species is variable in appearance— This species is found throughout These spiders inhabit caves, rock Found in the pastures and woods of
the abdomen, for example, may be brown or gray. the world. It lives in caves and crevices, and buildings, especially in Europe, often among leaf litter, this
in the cellars of houses, where warmer regions. They all look very is a common, ground-living spider.
the light levels are low. similar, and can be separated only
by examination of their genitalia.

Family Scytodidae long and are cream or yellow-brown Family Sparassidae Family Theridiidae
with black markings. Females carry
Spitting spiders the egg sacs under their body until Huntsman spiders Comb-footed spiders
the young emerge.
Occurrence 200 spp. worldwide, except Australia and Occurrence 1,000 spp. in tropical and subtropical Occurrence 2,000 spp. worldwide; in vegetation, under
New Zealand; under rocks, in buildings regions; on ground, tree trunks stones, in leaf litter, cracks, crevices

The common name of these 6-eyed SCYTODES THORACICA These drably colored spiders are Also called cobweb spiders, these brown
spiders comes from their unique Often found inside buildings in North America efficient, nocturnal hunters, able to to black arachnids have a comblike row
prey-capturing technique. Using a and Europe, this spider can squirt glue over 3⁄8 in move sideways with great agility. The of stout bristles on their hindlegs. The
rapid side-to-side movement of the (1 cm). Males are slightly smaller than females. larger species, also known as giant crab body is 1⁄16 – 1⁄2 in (0.2 – 1.5 cm) long and
chelicerae, they squirt 2 zigzag streams 30 – 300 eggs per sac and keep the spiders, can easily tackle lizards. The has a very rounded abdomen. Comb-
of sticky, gluelike substance from close sacs at the rear of the web. The bite of carapace and abdomen are flattened. footed spiders construct irregular webs,
range to stick the prey down. Spitting these spiders can be very dangerous, Legs may span up to 6 in (15 cm) and some of which may have sticky lines
spiders measure 5⁄32 – 3⁄8 in (4 – 12 mm) causing tissue degeneration. the body can be 3⁄8 – 2 in (1 – 5 cm) long. extending to the ground. Females are
There are 8 eyes of equal size, 4 of venomous and a few, such as the black
Family Sicariidae LOXOSCELES RUFESCENS which point forward from the front widow, are dangerous to humans. They
Common in Europe and introduced to Australia, edge of the carapace. lay up to 1,000 eggs per year, which
Six-eyed crab spiders the brown recluse spider may bite humans and they often guard in round, silk egg sacs.
cause unpleasant lesions that are slow to heal. spiny legs
Occurrence 124 spp. in warm parts of North and South slender legs with spherical
America, Europe, Africa; in shaded areas in rocks 8 eyes few fine spines abdomen
and bark
shiny
Also known as brown spiders because black
of their color, these arachnids have female
6 eyes, arranged in 3 pairs, and a
distinctly hairy body and legs. They are indistinct drab
1⁄4 – 3⁄4 in (0.6 – 1.8 cm) long and, in most black coloration
species, have a violin-shaped mark markings
on the carapace. They make sticky,
sheetlike webs, to which some species HETEROPODA SPP. LATRODECTUS MACTANS
keep adding as they grow. Females lay Huntsman spiders are pantropical species. Often The male of this species often dies shortly after
found in crates of bananas, they are known to mating and may be eaten by the venomous
bite warehouse workers but are not dangerous. female; hence the common name, black widow.

ARACHNIDS 593

Family Theraphosidae relying on their large size to subdue hairy tarsi
prey, which include small vertebrates
Tarantulas such as frogs, lizards, and birds. They prey BRACHYPELMA VAGANS
crush their prey with their large fangs, The Mexican red-rumped tarantula is a ground-
Occurrence 950 spp. worldwide, especially in pour digestive juices over the body, living species that hunts at night. It is found in
subtropical and tropical regions; in ground burrows, trees and then suck up the resulting liquid. semidesert and arid regions of Central America.
Females lay a batch of eggs in a burrow.
The name tarantula was originally An egg sac can be the size of a golf
applied to a wolf spider from southern ball and contain about 1,000 eggs.
Europe (see opposite), but nowadays Spiderlings stay in the burrow until their
it is far more often used for this family. first molt, and then disperse to find food
These are the giants of the spider and make their own burrows. Several
world, with bodies up to 43⁄4 in (12 cm) species of this family live for 10 – 30
long, and a legspan of up to 11 in years, and some are kept as pets.
(28 cm). Their bodies and legs are
covered in bristly hairs, and their POECILOTHERIA REGALIS pedipalps cheliceral fangs
coloration varies from pale brown to The tiger or Indian may be 3⁄8 in
black, with markings in pink, brown, ornamental spider is the (1 cm) long
red, or black. They are mygalomorphs, world’s largest tree-dwelling
like funnel-web spiders (see p.589), with spider, with a legspan of 61⁄2 in beige and brown BRACHYPELMA EMILIA
fangs that move up and down. When (17 cm). It is found in India and leg markings The Mexican red-legged tarantula lives
threatened, a tarantula will display its Sri Lanka. It hides in a silk-lined in burrows in desert and semidesert
downward-pointing fangs. The large retreat by day and hunts birds, regions of Central America. It kicks
size of tarantulas has led to the belief lizards, and arthropods at night. up the hairs of its abdomen as a
that their bites are fatal but only some defensive reaction.
species are venomous; in fact, the
venomous species are often relatively black, black triangle very hairy I N V E R T E B R AT E S
small. Tarantulas are nocturnal hunters, hairy at front of tarsi
femora carapace
legs covered
with hair legspan of
4 in (10 cm)

spinnerets dark-edged, pale
stripe down center
of abdomen robust,
hairy body
GRAMMOSTOLA ROSEA
Found in South America, especially in Chile, red hairs
the ground-living Chilean rose is one of the on tibiae
species most commonly kept as a pet
because of its docile nature.

Family Thomisidae change color. The female keeps her long front Family Philodromidae
eggs in a flat sac attached to plants, pairs of legs
Crab spiders and guards them until she dies. Running crab spiders

Occurrence 2,150 spp. worldwide; in meadows, Occurrence 600 species worldwide; in meadows,
gardens, on flowers, other parts of plants, tree bark gardens, on flowers, other parts of plants, tree bark

The common name derives from squat abdomen These small to medium spiders are
these spiders’ characteristic crablike shape broad generally colored with browns or grays,
sideways movement (although they can at rear and have a body covered in long hairs.
also move forward and backward) and MISUMENA VATIA They were formerly classified among
usually squat shape; however, some This goldenrod crab spider has the ability to Thomisidae (left), but are now
species are elongated. Crab spiders change its color in order to merge with the understood to be more
range from 5⁄32 to 1⁄2 in (4 – 14 mm) in surroundings. Mostly found on white or yellow distantly related to
length. The carapace is nearly circular, flowers, it is usually one of these 2 colors (see them. They are less
and the abdomen is short, often blunt above and left), but can also be pale green. inclined to ambush
ended. The first 2 pairs of legs, used to Common throughout Europe and North America, their prey—like true
seize prey, are larger and spinier than it can tackle large prey such as butterflies and crab spiders—and
the other 2 pairs. Crab spiders often bees. The female is much larger than the male. instead catch them
ambush insects landing on flowers— while on the run.
species that do so have very powerful
venom, which can easily kill a bee much TIBELLUS OBLONGUS
larger than themselves. Many species Widespread all across the northern hemisphere,
are colored white, bright pink, or yellow, this spider can be found in a variety of damp
to match the flowers, and a few can grassland habitats.

594 MOLLUSKS

Mollusks

PHYLUM Molluska Of all invertebrates, mollusks have arguably the Movement
CLASSES 7 widest range of body forms. They include gastropods
ORDERS 53 (slugs and snails), bivalves (such as oysters and Most mollusks use their broad, flat foot to creep over hard
FAMILIES 609 clams), cephalopods (octopuses, squids, and surfaces, often on a thin layer of mucus. Some bivalves are
fixed to the surfaces on which they live, and all are relatively
SPECIES About 110,000 cuttlefishes, among others), chitons, and several inactive, but they often have a well-developed foot, which some
species use to dig burrows in sediment. The most mobile and
less familiar forms. All mollusks have one or more fastest-moving of all mollusks are the cephalopods, especially
octopuses and squids. Using undulations of their muscular fins or
of the following: a horny, toothed ribbon in the mouth (the radula) that by flapping them, they can make a slow swimming motion but
they are also able to move more rapidly by squirting a jet of water
is unique to mollusks; a calcium-carbonate shell or other structure from the mantle cavity.

covering the upper surface of the body; and a mantle or mantle cavity, MUCUS TRAILS
To reduce surface friction, slugs and
typically with a characteristic type of gill. Mollusks are adapted to life snails secrete mucus from their foot.
Slugs (such as this striped slug) have
on land and in water; there are also many parasitic species. lost their shells, and generally move
more quickly than snails.

I N V E R T E B R AT E S Anatomy

Most mollusks consist of 3 parts:
a head, a soft “body” mass, and a
muscular foot, which is formed from the
lower surface of the “body” mass and
used for locomotion. In some mollusks,
the head is well developed and supports
sophisticated sense organs, but in others (such
as the bivalves), it is effectively absent. The upper
surface of the “body” mass is covered by a layer called
the mantle, from which the shell is secreted. Retractor
muscles can be used to pull the shell over the body for
safety. Besides protection, the shell may be used as an
organ for burrowing or controlling buoyancy. A fold in the
mantle forms a cavity that in aquatic mollusks houses the gills.

coiled digestive mantle shell hinge arm SQUID SCHOOL
shell system gill siphon ligament jaw
radula All cephalopods are marine. Octopuses tend to be solitary
mantle digestive funnel but squids commonly form schools, species of the genus
system Loligo being particularly sociable. Cuttlefishes only
sensory shell congregate in the breeding season.
tentacles tentacle
gills
eye
digestive system
foot radula adductor gills foot Feeding
muscle mantle cavity
GASTROPOD Mollusks include predators, grazers,
Gastropod snails have a BIVALVE CEPHALOPOD and browsers, as well as species
coiled shell, a large foot, In cephalopods, part of the that feed on deposited or suspended
and a distinct head, with Bivalves are enclosed within head and foot are modified to material. Many bivalves and a few
eyes and sensory tentacles. a pair of shells, from which form arms and a funnel into gastropods are filter feeders, using
Slugs have no shell. the foot and siphons can be the gill chamber. The shell is their gills to strain particles as small
extended. The gills are often small or absent entirely. as bacteria from water. Cephalopods
large and folded. are carnivores. They use their long
arms, which are often equipped with
BIVALVE SHELL GASTROPOD SHELL suckers, to catch fishes, crustaceans, HUNTING
and other prey. These relatively Some octopuses are capable of subduing large
The 2 halves of a bivalve’s shell are joined In most snails, the shell is secreted unevenly intelligent animals have been known and formidable prey. This one has overpowered
along one edge by elastic material and closed from the mantle, which causes it to coil into a to stalk prey. Besides their radula, a zebra moray eel.
by contracting the adductor muscles. clockwise spiral (occasionally counterclockwise). cephalopods have a parrotlike beak,
which they use to bite their prey. RADULA
Most other mollusks feed on food The tiny, toothlike denticles
ranging from attached algae, plants, on the radula, which may
and animals to planktonic jellyfish number up to several
and even slow-moving fishes. thousand, are used like
Parasitic species obtain nourishment a rasp to collect small
from their host.
particles of food.

MOLLUSKS 595

Class Bivalvia of bivalve mollusks vary greatly, from distinctive, fan-
less than 1⁄16 in (2 mm) to as much as shaped shell
Bivalves 31⁄4 ft (1 m) across. The largest species SCALLOPS
(giant clam) is about 2 billion times Unusually among bivalve mollusks, scallops can swim using a form
Occurrence c.15,000 spp. worldwide; in aquatic heavier than the smallest. Bivalves are of water-jet propulsion, to which they usually resort to escape
habitats, mostly on the sea bed, but some in freshwater usually static, although some—for predatory starfish. This North Atlantic species, Aequiptecten
example, scallops—can swim. Most opercularis, may attain a diameter of 31⁄2 in (9 cm).
Bivalves are the only mollusks that have are filter feeders, using modified gills
a shell consisting of 2 parts, called to strain food from the water current.
valves, hinged together. In most cases, The water is drawn in and pumped
the valves can be closed tightly to out through tubes or siphons—
protect all or a large part of the animal’s especially important for species that
body. Mussels, clams, oysters, and live buried in mud or sand. The siphons
scallops are among the most familiar may be so large as to be permanently
bivalves, providing a valuable source outside the shell. Bivalves have tiny
of food for humans as well as other heads, and they do not have a radula—
creatures. Some species, such as the the mouthpart that other mollusks use
piddock and shipworm, have small, to rasp away at their food. The sexes
sharp-edged valves, used like drill bits are separate, although some bivalves
to bore through wood or soft rock. Sizes may be hermaphrodite.

flat shell

MUSSELS SADDLE OYSTERS THORNY OYSTERS EDIBLE OYSTERS I N V E R T E B R AT E S
Mussels attach themselves to hard surfaces by Like true oysters, saddle oysters or jingle shells The tropical thorny oysters, found mostly on The edible oyster cements its left-hand valve
means of small threads, allowing them to hold live with one valve attached to a hard surface. rocky outcrops and coral reefs, grow up to directly onto a surface such as a rock or shell,
fast against wave action and water currents. The method of attachment is peculiar: a calcified 8 in (20 cm) in diameter and have shells so that the animal lives lying on its side. A
They often live in large clusters, and can cause plug passes from the upper valve through a hole covered with elongated spines, as in the valued food source since prehistoric times,
problems for coastal power stations by blocking Spondylus species pictured above. Their oysters are among the most popular of edible
their cooling systems. Mussels are often raised shells often become covered with algae, mollusks. This North Atlantic Ostrea species
in aquaculture systems. Mytilus edulis (above), which may serve as camouflage. may grow up to 4 in (10 cm) in diameter.
a species found in northern waters, may be 6 in
(15 cm) long. ribbed long, slender
shell valves

in the lower one onto the surface. The Atlantic
Anomia ephippium (above) is about 21⁄4 in
(6 cm) long.
large, fluted
shell

respiratory
siphon

fleshy COCKLES RAZOR CLAMS
mantle Cockles live in sandy sediments, Razor clams are
burrowing just below the surface so-called because of their
GIANT CLAMS so the body is half in and half out resemblance to closed “cut-throat”
The tropical, reef-dwelling giant clam, Tridacna sp. (above), is the largest bivalve; it may of the sand. The shell is usually razors. Occurring in almost all
measure more than 31⁄4 ft (1 m) across and weigh over 440 lb (200 kg). Contrary to popular strongly ribbed, stout, and latitudes, they inhabit deep, vertical
myth, it is harmless to humans. As with all giant clams, most of its dietary needs are met by semispherical. Several species, burrows in sandy sediments, using the
symbiotic algae that live in its fleshy mantle; using sunlight, the algae produce a supply of including the Atlantic Cerastoderma shell valves to wedge themselves in. The
energy-rich food. The clam also filters microscopic particles of organic matter from the sea. edule (above)—which is 2 in (5 cm) species whose shell is shown here, Ensis siliqua,
high—are harvested commercially. may grow up to 10 in (25 cm) long.
SWAN MUSSELS PIDDOCKS
Most bivalves are marine, sculpted shell Using their elliptical shells like drill bits,
but some—such as this
swan mussel—inhabit piddocks bore into materials such as
freshwater. A species of the rock, wood, peat, and clay, and live in
genus Anodonta, it is found the excavated burrow. Some piddocks
in North America and are phosphorescent, glowing with a ghostly
Eurasia, and can grow to blue-green light at night. This North Atlantic
9in (23cm) across. Their species, Pholas dactylus (left), may be up
shells are thin, mainly to 6 in (15 cm) across.
because calcium is less
readily available in fresh- SHIPWORMS
water. In their larval stages, These wood-boring bivalves occur
they are parasitic on fishes. in all seas, but are particularly
common in warm waters. The
relatively small shell is used to
gouge out a tunnel in which to live,
and the shipworm lines it with a
chalky tube. Their bodies may
extend up to 61⁄2 ft (2 m), although
the common shipworm, Teredo
navalis (pictured), rarely exceeds
a tenth of this size.

596 MOLLUSKS

Class Gastropoda a spiral shell and move by creeping characterized by torsion, a process SEA HARES
on a muscular foot, but there are many in which the mantle cavity is rotated Most sea hares have a thin shell (not visible
Gastropods exceptions to this rule: some,for counterclockwise up to 180 degrees, externally), a large, well-developed head with
example, have no shell at all. Other until it faces forward and is positioned 2 pairs of tentacles, and a large foot. Sea hares
Occurrence c.75,000 spp. worldwide; in aquatic characteristic features include a large over the head. This occurs early in larval inhabit beds of seaweed and sea grasses, where
habitats (mostly bottom-dwelling), in wet, damp, and head, with eyes and tentacles, and development and means that the they feed on large, fleshy algae. The North
dry regions on land a ribbon-shaped mouthpart called a digestive, reproductive, and excretory Atlantic species shown above, Aplysia punctata,
radula, which is armed with small, often systems all discharge through the one may attain a length of more than 12 in (30 cm).
Habitat All microscopic, teeth and is used to rasp opening in the shell. Gastropods feed
away at food. These mollusks vary in a wide variety of ways: they may be
This vast and variable group of widely in size, and can grow up to 31⁄4 ft hunters, browsers, or grazers; some
invertebrates includes over four-fifths (1 m) long. The shape of the shell is are suspension or deposit feeders;
of the mollusks alive today. The familiar highly variable—some form a tall spire, some are parasitic. Although sexes are
garden snail, slug, winkle, sea hare, sea while others flare outward. In some separate in most gastropods, several
slug, abalone, pond snail, and conch species, an operculum, or “door,” shuts groups are hermaphrodites, while in
are all gastropods. Typical species have the shell opening when the animal other groups, animals change from one
withdraws inside. Gastropods are sex to the other during their lifetime.

LIMPETS spreading HELMET SHELLS
Found on rocky shores, limpets, like abalones, lip The stout, colorful, and attractive helmet shells
graze on young algae, using their conical shells resemble the helmets worn by the gladiators of
to protect themselves from the waves. Of the 2 ancient Rome. The shells may be more than
Atlantic species shown here, the common limpet, 12 in (30 cm) long. The animals that make
Patella vulgata (left)— 2 in (5 cm) across— them inhabit sandy sediments in the tropics,
wanders over rocks, while the blue-rayed limpet, feeding on other mollusks and sea urchins. The
Ansates pellucida (below)—up to 3⁄4 in (2 cm)
across—creeps over kelp, feeding on small shells of species such as the horned
helmet, Cassis cornuta (left), are much
epiphytic algae and on the kelp itself. Many used as ornaments and for carving.
rock-dwelling limpets are strongly
I N V E R T E B R AT E S territorial, making circular scars in
the rock where they stay locked
in position at low tide.

conical blue long spines
shape “ray” MUREXES
mucus raft These gastropods
are predators, often
COWRIES VIOLET SEA SNAIL consuming other
The beauty of their glossy shells The violet sea snail, Janthina janthina, mollusks and barnacles
ensures that the mostly tropical is one of the few shelled gastropods after boring a hole
cowries are particularly sought that inhabit the ocean surface. It does through their shells.
after by collectors. In life, the this by secreting a raft of mucus Several secrete a
shell is covered by a flap bubbles that keeps it afloat. This purple substance
of skin, which is a part of warm-water snail is blind and has that has been used for
its brightly colored mantle. a paper-thin shell, 3⁄4 in (2cm) across. centuries as a dye. Murex
The shell aperture is long and It feeds on by-the-wind-sailors (see troscheli (right), which is
narrow, which helps to protect p.540) and other colonial hydroids found in the Indo-Pacific, has
the cowrie from attacks by that drift through the water. a shell that is 6in (15cm) long,
predatory crabs. This species, with elongated, spiny extensions.
Cypraea ocellata, can grow
up to 21⁄4 in (6 cm) across.

patterned iridescent
shell interior

HARP SHELLS smooth ribs CONE SHELLS holes to
The globular harp shells have Cone shells are highly expel water
smooth, regularly spaced ribs, dangerous predators: and waste
which resemble the strings using their harpoonlike ABALONES
of a harp. Up to 4in (10cm) mouthparts, they attack fish Also known as ormers, awabis, or ear-shells,
long, the shells are often and other animals, injecting abalones are grazing animals that can be over 8 in
brown, red, or pinkish. a venom so potent that it has (20 cm) across. Their shells have a distinctive series
Species such as Harpa been known to cause death in of holes, through which the water current drawn into
major, shown here, are humans. The West African garter the gill chamber leaves, as do waste products. The
mainly nocturnal, and inhabit cone, Conus genuanus, shown iridescent shells of species such as the red abalone,
tropical sandy sediments, here, is a typical example, with a Haliotis rufescens (above), found off the west coast
into which they burrow. When highly decorated, tapering shell up of North America, are used to make jewelry, and the
disturbed, they may discard part to 2 3⁄4 in (7 cm) long. animals inside are often eaten.
of the large foot, in much the same
way as a lizard discards its tail.

MOLLUSKS 597

fingerlike
tentacle

colorful light shell
papillae FRESHWATER SNAILS
Both the European ramshorn snail,
SACOGLOSSANS SEA SLUGS Planorbarius corneus (pictured below),
Sacoglossans are sluglike marine gastropods, 3⁄8 in (1 cm) or so True sea slugs lack shells which can grow up to 11⁄4 in (3cm) across,
long, that graze on algae, sucking up the contents of their cells. and are often brightly colored with striking patterns. Many and the great pond snail, Lymnaea stagnalis
This species, belonging to the widespread genus Elysia, gets its species, like Janolus nakaza, above—which is 31⁄4 in (8 cm) (above), which is up to 2in (5cm) tall, have
color from chlorophyll—the bright green pigment that algae use across and lives on reefs off the southern coast of Africa—have a single lung instead of gills. Because they
to harness the energy in sunlight. colorful protuberances (papillae) on the back. Most sea slugs breathe air, they can survive in slow-flowing
live on the seabed, although a few are planktonic. or stagnant water, where oxygen levels are
low. The great pond snail and its many
stalked eyes near base relatives are common in freshwater
eyes of tentacles throughout the Northern Hemisphere.

respiratory opening flattened, spiral shell I N V E R T E B R AT E S
TERRESTRIAL SLUGS thin, whorled shell
Unlike sea slugs, terrestrial slugs breathe air
through their mantle cavity, which functions
as a lung. In this European black slug, Arion
ater, usually 6 in (15 cm) long, the opening
leading to the cavity can be seen just
behind the animal’s head.

TERRESTRIAL SNAILS eyes at tip
Land-dwelling snails differ from sea of tentacles
snails in having thin, relatively light
GHOST SLUG shells. Many also lack an operculum— large, muscular foot
This slug avoided detection until 2007—when it was discovered a hard plate that seals the shell’s
in Wales by a researcher. Selenochlamys ysbryda prey on opening. The species pictured right is the
earthworms at night: ysbryd is Welsh for “ghost.” It is unlikely giant African snail, Achatina fulicula, which
to be native to the UK. can reach a length of 12 in (30 cm) with its
body extended. Originally from East Africa,
WINKLES it has been introduced to many parts
Winkles are small marine grazers common on rocky shores, in of southern Asia, and in some regions
mangroves and salt marshes, and more rarely on mudflats. Some is a serious agricultural pest.
can live at the very top of the shore, where they are wetted only
by high spring tides; these species have a gill chamber partly coiled tip WORM SHELLS red shell siphonal
converted into a lung. The European flat periwinkle shown above, irregular These mainly tropical canal
Littorina obtusata, like most species of winkle, is usually less adult growth gastropods start life with tightly
than 11⁄4 in (3 cm) tall. coiled shells, but as they grow older,
the coils become wider and more
TOP SHELLS irregular, making the shells look as if
Top shells are grazing marine they have been unwound. This Caribbean
gastropods with a conical shell up species, Vermicularia spirata, grows up
to 11⁄4 in (3 cm) high, which has a to 4 in (10 cm) long. Like many other worm
flat, circular base. They occur on shells, it secretes a mucus filter from its
foot, and uses this to trap small animals.
many rocky shores and reefs.
Some, like the widely HETEROPODS TULIP SHELLS operculum
distributed Calliostoma The species of the warm- The spindle-shaped tulip shells or
species shown above, are water genus Carinaria and horse conches are predators on other mollusks and worms.
its relatives are among the Although some live in shallow water and in high latitudes,
brightly colored. Males have no few gastropods that have most prefer warm water and the sublittoral zone (below the
penis, and fertilization is external. taken up life in the open sea, shell low watermark). The body is often red, as in the Fasciolaria
where they make up part of
the plankton. These unusual species above, and the shell, up to 10 in (25 cm) long, has a
mollusks, up to 2 in (5 cm ) long, long, tubular projection—the siphonal canal—at the front.
have gelatinous bodies and
either very thin shells or no shell
at all. They appear to live upside
down because the shell, if present,
is located beneath the body,
and the fin—a foot modified
for swimming—is uppermost.

598 MOLLUSKS

Class Aplacophora Class Polyplacophora a single structure. Chitons graze algae particular site where they fit snugly

Aplacophorans Chitons from rocks on the seabed. They creep against the rock, helping to protect

Occurrence 395 spp. worldwide; on the seabed or in Occurrence 950 spp. worldwide; on the seabed slowly over the surface—often after themselves from attack, and from
association with other animals (especially cnidarians)
Chitons resemble gastropods in having dark or at high tide—and return to a desiccation if exposed to the air.
With their thin, wormlike bodies, a suckerlike foot, but their shells are
aplacophorans bear very little quite distinctive, being made of 8 plates. slight gloss
resemblance to any other mollusks. These are arranged in a line, and they on plates
Typically less than 3⁄16 in (5 mm) long, arch over the animal’s back. These fat,
they have no trace of a shell, but are oval to elongated mollusks are covered thick CHITON STRIATUS
covered by a tough cuticle that contains by a thick “girdle,” which often flanks the girdle Found on the west coast of South America, the
a large number of small, mineral spicules. plates like a lip. It has a rubbery texture,
They have poorly developed heads and and in many species is covered with magnificent chiton is large and well arched and
no eyes, and move by creeping or bristles or calcareous spicules. Chitons surrounded by a broad girdle. It measures 31⁄2 in
by burrowing through sediment. The can be up to 16 in (40 cm) long. They (9 cm) in length and inhabits intertidal rocks.
creeping species feed on cnidarians, have a large, muscular foot, a small The central portion of each plate has crowded,
while the burrowers feed on tiny animals, head with a well-developed rasping straight riblets that are usually worn smooth
or on particles of organic matter. Some mouthpart (radula), but no eyes or at the highest point. Head and tail plates have
species have separate sexes, but most tentacles, and a U-shaped mantle cavity coarse, radiating ribs, and the girdle is covered
are hermaphrodites. Some keep their around the foot with 6 – 88 pairs of gills. with polished granules.
eggs until they hatch, but little else is In both sexes, there is one pair of
known about their breeding habits. gonads (reproductive organs) fused into ACANTHOPLEURA GRANULATA
The fuzzy chiton is a strongly
I N V E R T E B R AT E S head humped chiton from the
Caribbean. It is
body covered with surrounded by a
backward-pointing thick girdle that
spicules is covered with
coarse spines. The
plates are brown
when unworn,
but usually appear
grayish brown with
darker brown crests
and sides. Up to
21⁄4 in (6 cm) in
length, it inhabits
intertidal rocks.

CHAETODERMA SPP. head end
Members of the genus Chaetoderma, found MARBLED CHITON
in the Northern Hemisphere, are relative giants Tonicella marmorea, a North Atlantic
among aplacophorans, growing up to 31⁄4 in chiton up to 11⁄2 in (4 cm) long, has a
(8 cm) long. Like other aplacophorans, they broad, leathery girdle surrounding the
lack a foot. They breathe with gills, located shell plates. It can be found from the
in a cavity at the back of the body. intertidal zone to depths of 650 ft (200 m).
It occurs on rocks, stones, and pebbles,
and in some Scottish sea lochs can attain
densities of 50 per square yard.

Class Monoplacophora Class Scaphopoda The sexes are separate, and ELONGATED TUSK respiratory
there is a single reproductive Antalis species are current passes
Monoplacophorans Tusk shells organ. Living tusk shells are a small group of marine in and out
rarely seen, but their empty mollusks from the North of aperture
Occurrence 30 spp. in Atlantic, Pacific, and Indian Occurrence About 580 spp. worldwide; on the seabed, shells, which can be up to Atlantic that live in shells
oceans; at depths of 650 – 23,100 ft+ (200 – 7,000 m) in soft sediments 6 in (15 cm) in length, 21⁄4 in (6 cm) long. They
are often washed up feed on microorganisms,
Monoplacophoran mollusks were Widely distributed in all the world’s on the shore. using numerous club-
thought to have become extinct oceans, these burrowing mollusks shaped tentacles.
more than 300 million years ago, until are easily recognized by the shape
a handful of specimens were dredged of their shells, which are like tapering, raised, small pipe
up in the eastern Pacific Ocean in 1952. hollow tusks, open at both ends, with longitudinal ribs at rear end
Since then, they have been found on the one opening larger than the other. alternating
deep seabed in widely scattered parts Tusk shells live head downward color rings
of the world. Monoplacophorans look like in sediment, the head and the
limpets (see p.596), but they each have foot protruding out of the larger of ELEPHANT TUSK BEAUTIFUL TUSK
up to 8 pairs of foot retractor muscles, the shell openings. The small head The solid and slightly This species, Pictodentalium formosum,
whereas limpets and other gastropods has numerous fine, ciliated feeding glossy shell of the found on Indo-Pacific coasts, grows
have just one pair. A horseshoe-shaped filaments, which contract to transport species Dentalium to 3 in (7.5 cm) in length. It differs from
mantle cavity containing 3 – 6 pairs of gills food particles from the sediment into elephantinum has other large tusk shells in its head end
surrounds the foot. The shell is conical the mouth. The smaller aperture a characteristic notch being only slightly broader than its rear
or cap-shaped, and the head is small, projects above the sediment surface; at its narrower end. This end; it is also straighter than most. Its
with a large mouthpart (radula). There respiratory water current is drawn in mollusk inhabits offshore longitudinal ribs and riblets are crossed
are no eyes or tentacles. Sexes are and let out through this opening. sands in the Indo-Pacific, by concentric growth lines. A small,
separate. These mollusks grow up There are no gills; instead, gases are and is 3 in (7.5 cm) long. notched pipe protrudes from the rear end.
to 11⁄4 in (3 cm) long. exchanged through the mantle surface.