Letters of the Insect World for video

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Table of Contents

Letter from the Author 8
Musings of a Mayfly 11
A Prophesy of Doom 15
The Curse of a Name 18
The Grave Digger 21
Flying High 24
Digging up the Dirt 28
Homes made to order 32
The Life of a Workaholic 35
The Silk Road 38
Lighting up the Night 41
Masters of the Air 44
The First Farmers 48
Back from Extinction 52
Walking on Water 55
The Magical Insect 58
A Sullied Reputation 62
The Celebrated Stonemason 66
And the Winner is . . . 69
Glossary 72

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Letters from the Insect World
10

Musings of a Mayfly

Musings of a Mayfly

Allow me to introduce myself. I am a mayfly nymph. Along with a great
many of my relatives, both close and distant, I belong to the distinguished
order of the Ephemeroptera – an order that goes all the way back to the early
Carboniferous era, making ours one of the oldest orders of living insects.
We predate the dinosaurs. Back in that far-off time my ancestors inhabited
a damp, oxygen-rich world that allowed them to grow to a great size – about
a foot and a half long. That’s eighteen times the size of their biggest present-
day descendants.

The name of our order is derived from two Greek words – ephemera
meaning short lived and ptera meaning wings. But the name is misleading.
I will soon be a year old, which is a fairly good age for an insect.

Most humans are only aware of the winged adult mayflies that emerge
from ponds and streams, sometimes in such great numbers that they stop
traffic. These clouds of insects mostly live for only a single day. Their
job is to mate and produce the next generation of mayflies. In their new
terrestrial world, they don’t get to sip nectar from flowers like a butterfly.
Nor do they get to munch on juicy leaves like a caterpillar. Adult mayflies
have no functional mouthparts. But they have no thoughts of food as
they experience the magical freedom of the air. They have found a new
dimension as they fly upwards and drift down and then up again, part of a
synchronized mating dance, their wings touched with gold as they reflect
the setting sun.

Being such fragile creatures and with such a brief adult life, the females
almost always lay their eggs close to their childhood home. They don’t

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Letters from the Insect World

use their newfound joy of flight to disperse. Even so, mayflies are found
all over the world in just about every country and island, except the frozen
continent of Antarctica. The reason mayflies are so widespread is because
of their long history. Ephemeroptera were well established before the
landmasses drifted apart. When that happened, mayflies in what became
Australia and New Zealand were isolated from one another and from the
rest of the world. And so it was with mayflies in other places, leaving them
to gradually evolve into the insects we are now, each species recognized by
its own name.

But I digress. Let’s get back to my own personal journey.
Last year, after her mating dance, my mother flew upstream
and dipped down toward the sparkling water where,
piercing the surface film, she laid several tiny eggs. She
did this again and again. When she had laid around five
hundred eggs her life’s work was over.

As the eggs drifted down to the streambed some were
eaten by hungry predators, but a large number survived,
their rough exteriors anchoring them to a rock or stone. A
couple of weeks later, one of those eggs hatched. And there I
was, a mayfly nymph!

According to the dictionary, a nymph is a mythical spirit
of nature imagined as a beautiful maiden inhabiting, woods,
rivers, and streams. The definition describes me well. I have
a long slim body and three slender tails that almost double
my length. Being an insect, I am blessed with six legs, each ending in a
claw. A series of small plates or gills on both sides of my abdomen enables
me to take in oxygen from the water. My head is decorated with two antennae
and I boast five eyes – two compound eyes and three simple ones called
ocelli. Unlike my parents, I have strong mandibles designed for scraping
diatoms and algae from the rocks and stones that are my underwater home.
I also subsist on detritus, which is a polite name for plant garbage.

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Musings of a Mayfly

When I first hatched from my mother’s egg I must have been a tiny thing.
I don’t recall those days when I was apparently small enough to be
overlooked by all the hungry creatures that share my underwater world.
But now I have to be forever watchful. Enemies are everywhere – swiftly
swimming fish and sluggish leeches, crayfish with grasping claws and
carnivorous insect larvae, such as stoneflies, caddisflies, dragonflies and
alderflies.

This circle of eat or be eaten is one reason that humans respect mayflies.
Occurring, as we do, in large numbers, we are an important part of the
food chain. We feed the trout that fishermen love to catch for sport. It isn’t
comfortable to be valued simply because we are part of the food chain.
But aren’t we all? Even the fisherman, who casts his rod in my stream, will
some day deliver his body back to the great cycle of nutrients that sustain
our world.

Humans also value us as a gauge of water quality. They call us
bioindicators. If pollutants contaminate the pristine water of my stream,
then I, along with many of my relatives, disappear since we are creatures
that require clear, cool water. If fire consumes the trees that grow along
the stream’s edge or if humans or their cattle destroy the vegetation, then
the sun beats down on the water, heating it to a temperature that no longer
allows us to breathe. Our numbers fall away.

If my home becomes polluted, I don’t have much choice about where to
go. I’m not a strong enough swimmer to fight the current, so that rules out
going upstream. My only choice is to travel downstream. I have done this
on occasion, though not because of pollution. I had to move when I ran out
of food under my favorite rock. We mayflies usually join the drift at night
under the cover of darkness, which provides us with some protection from
our enemies. Even so, it is a dangerous, if exciting, time.

Becoming part of the drift is not the only time I’m vulnerable. Like
all insects, I have a rigid exoskeleton. Although this provides me with
protection, it also makes it hard for me to grow from a miniscule nymph to
the size I am now. When I have grown so much that there is no more room

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Letters from the Insect World

to expand, my exoskeleton splits. Underneath is a new elastic skeleton that
allows me to grow. Until it hardens I have no protection, except to be still
and wait. I have gone through the process of molting more than fifteen
times. Right now I again feel the pressure of my growing body fighting
against my rigid skin.

This time, I’m not concealing myself under a rock. Instead I am floating
up toward the sun and toward the greatest adventure of my life. I’ll use
my clawed feet to attach myself to a waterweed above the surface of the
stream. When my old skeleton splits down my back, it will reveal a new me.
I’ll emerge as a winged adult and fly off to a sheltered resting place nearby,
where I’ll spend the night and most of the following day. My colors will be
muted—good for camouflage—and my wings opaque. At this stage I will
be a subimago. I have to molt one more time to become a true shimmering
adult. Mayflies are the only insects that molt after they have wings.

This final molt will ready me to become one with—in the words of
the poet laureate Richard Wilbur—a ragged patch of glow with sudden
glittering. There is surely no better ending to my journey than to be part of
that sudden glittering!

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A Prophesy of Doom

A Prophesy of Doom

If humans happen to find me swaying gently on a leaf, my folded forearms
pointing up towards the sky, they see me as a gentle creature, quietly saying
grace before enjoying my next meal. How wrong they are! I am a vicious
predator, the tiger of the insect world. They call me a praying mantis, but
they would have been better to spell praying with an “e.” The name mantis
comes from the Greek word for a prophet. All that I prophesy is doom for
any insect or small creature that invades my space.

I am a patient being. I sit still, letting my eyes do the hunting. I have
five eyes. Two are bulging compound eyes with 3-D vision. My three small
ocelli detect movement. I can swivel my head through 180 degrees on my
long, slender neck, allowing me to focus sharply on any unwary creature
that happens to land close by. When my prey is within range, my strong
forearms spring into action with such precision that the motion has been
copied by two grandmasters of the martial arts in China. I assume they are
from opposite ends of China because the moves are known as the Northern
Praying Mantis and the Southern Praying Mantis. Those moves are now
used in the rest of the world, but a martial artist lacks the feature that makes
it impossible for my opponent to escape. I am equipped with a row of sharp
claws along the inner side of my forearms. When I strike, I impale my victim,
draw it close, decapitate it with my beak-like mandibles, and then enjoy my
meal.

We praying mantises have mastered the art of disguise. Many of us
have long, slender bodies and take on the fresh green color of the leaves
or grass where we like to perch. This is helpful in keeping us safe from

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18

The Curse of a Name

The Curse of a Name

We have probably met at some time or another, although I spend most of
my time hiding in crevices or in piles of rotting leaves. In spite of the fact
that I am a shy, gentle creature, humans tend to fear me or, at the very least,
to dislike me. This is all because of a name I was given centuries ago. I am
known as an earwig. The name comes from the Old English words ëare
meaning ear and wicga meaning beetle. This was due to a frightening old
wives’ tale that we hide inside ears, where we lay eggs that hatch into grubs
that feed on peoples’ brains. I have never seen humans pulling earwigs out
of their ears. Since we rarely take to the air, a human ear is fairly inaccessible.
And brains are not part of our diet.

Moreover, I am not a beetle.
Beetles belong to a different order – the order Coleoptera. Beetles
are named for their shieldlike front wings. Earwigs belong to the order
Dermaptera coming from the Greek words for skin and wings. Our front
wings form a leathery case over our hind wings. Those hind wings are unique
in the insect world. They are semi-circular with radially arranged veins and
they unfold like delicate fans. To be honest, they are not very efficient. That
may be why we are not often airborne. If we do leave the ground our flight
is rather fluttery and undirected.
Another reason that humans distrust us is because we are equipped
with paired hornlike pincers called cerci attached to the end of our
abdomens. The cerci of the male earwig are curved like claws whereas,
being a female, my cerci are almost straight. Most insects that have horns
wear them on their heads, but seeing we spend much of our lives wriggling

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Letters from the Insect World
38

The Life of a Workaholic

The Life of a Workaholic

Humans talk about being as busy as bees. How right they are! We work
incredibly hard to produce the honey that both sweetens their breakfast
cereal and provides us with food during the cold winter months when all
the flowers are gone. It takes us around 40,000 flight miles to produce just
one pound of honey. Some days I visit as many as 2,000 flowers in my search
for pollen or nectar.

Almost a lifetime ago I was one of the hundreds of eggs our queen lays
every day, each of them carefully placed in its neat hexagonal cell. I emerged
from my egg in just three days to become a pampered larva, constantly fed
and groomed. Most young insects have to fend for themselves, but there I
lay, snuggled up in my own cozy room, with scores of attendants feeding
me super-rich, tasty food. I grew up fast. After I had cast my exoskeleton
several times, my caretakers sealed my cell with wax and left me to spin
a cocoon and become a pupa. About ten days later I chewed my way out
through the protective cap. I was now an adult, one of the hive’s vast colony
of female worker bees. No other word than worker can better describe my
role.

At first I stayed within the confines of the dark walls of the hive. My job
was to care for a new batch of hungry larvae in the nursery, feeding them,
and repairing their cells. I was then promoted to tending the queen, only to
be transitioned to the less happy task of janitorial work. That included taking
care of the dead, dragging them to the edge of the platform at the door of
the hive and tipping them to the ground below. This gave me my first view
of the outside world. I next became a guard at the hive entrance. Armed

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Lighting up the Night

there are only a few random specks of light, but soon the fireflies find their
rhythm—five to eight flashes and then everything goes dark for six seconds,
followed by more flashes and another six-second pause. Meantime, the
female fireflies hidden down among the leaf litter send back messages to
the males during the six seconds of darkness.

Fireflies are proud to be admired by humans, but when you young
humans rush out into the darkness intent on catching us in canning jars,
please don’t keep us trapped for long. We have important work to do, and
not much time to light up the night.

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The First Farmers

The First Farmers

Around 12,000 years ago, there were humans who gave up being nomadic
hunter-gatherers and settled down in farming communities. This happened
over a period of time and in different areas of the world, with people
cultivating plants that already flourished in their region—cereals in Syria,
rice in China, potatoes in Peru, and squash in Mexico. They domesticated
animals as well as plants—sheep and cattle in Turkey, pigs in Mesopotamia,
and llamas in the Andes.

In places where farmers were busy providing food, the rest of the
population mostly lived in villages and towns with time on their hands to
follow other pursuits. In Mesopotamia they developed cursive writing,
studied mathematics and astronomy, and invented the wheel. As the use
of the wheel spread, it was eventually followed by the invention of tools
and machines that resulted in farmers being able to feed more people. Over
the centuries farming grew into an industry that depended on machinery,
irrigation, and chemicals. Today, successful farmers often grow only one
crop in vast fields or orchards – a monoculture.

I, too, belong to a group of successful farmers who tend a monoculture.
We are known as leaf-cutter ants, though cutting chunks out of leaves is

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Letters from the Insect World
One clue they have uncovered is that we emerge when the temperature
eight inches below the surface of the soil measures 64 degrees. But that
happens every year, so it can’t be the trigger. Humans also think that we
might be able to tell the passage of the years by the annual rise and fall of
the sap in the roots of the deciduous trees we feed on. But that would mean
that a humble insect nymph could count up to seventeen!

So how did I know when to emerge? The answer surely lies in the
name Carl Linnaeus gave me. I am Magicicada septendecim, the magical
cicada. If I were to tell you the answer, my magic would surely be gone—
and with it my magical name!

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A Sullied Reputation


A Sullied Reputation

If you were to ask humans which insects they most fear and despise, I’m
sad to say I’d be near the top of the list. It is so undeserved. I do ever so
much good in the world. If humans would just leave me alone and allow
me to get on with hunting down the flies, caterpillars and a host of other
creatures that cause them and their crops problems, we would get along
fine. Humans don’t seem to realize I am fighting on their side.

As a member of the yellow jacket family, I am well equipped for my
dual roles of hunter and scavenger. I’m an excellent flier with the ability to
hover while I search out prey with my large eyes. But my best feature is my
strong, cutting jaws. My mandibles can make short work of the fat caterpillar
that is feasting on lettuce or cabbage leaves in the vegetable garden. I love to
hunt down mosquitoes and I can knock a house fly senseless with a single
bite. I sometimes even snatch dead ones from a spider’s web. By ripping
the flesh from the rotting corpses of small birds or mammals till all that is
left is bare bones, I help to control the fly population by depriving them of
breeding places.

While I’m an adult I consume the high-energy sugars that are found
in nectar, tree sap, and fruit juices. I’ve even been known to sip soda pop
when I get the chance. So to explain why, in spite of my vegan diet, I often
hover over the hamburger or salmon that’s cooking on the grill, I need to
tell you our life story.

Yellow jackets are social insects. For most of the summer, we workers
live in a large colony of females whose role is to take care of our queen, our

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crossed flies with red eyes and flies with white eyes, flies with crumpled
wings and flies with straight wings, and flies with bristly legs and flies with
smooth legs.

Because fruit flies have a rapid life cycle, experiments yield quick
answers. Also it’s easy to tell the female and male insects apart, which is
helpful to humans who are interested in breeding us in laboratories. The
females are bigger than the males and are lighter in color.

To illustrate our life history, let me tell you my own story. The egg my
mother laid in a juicy peach took just over twelve hours to hatch. I spent the
next four days as a larva, molting twice. After nine days as a pupa, I emerged
as an adult. So here I am a mature female, ready to mate and lay eggs in less
than two weeks. Lots of insects spend months in the larval stage. There’s a
cicada that spends seventeen years under the ground before emerging as
an adult, but that’s an extreme case.

I am one of the lucky fruit flies. Millions upon millions of Drosophila
don’t get to spend their young life inside a bruised peach; nor do they have
the freedom to choose their own mate when they are adults. They are reared
in glass tubes on a diet of cornmeal, sugar, and yeast and are then sold to
laboratories or classrooms, where they are examined under microscopes.
To make sure they don’t fly away while they’re being studied, they may be
given a dose of carbon dioxide to put them to sleep. Sometimes, they’re put
in freezers for a few seconds and are examined while they’re still in a frozen
state.

Scientists are no longer just interested in the mutant genes that are
found in fruit flies in the wild, like those that affect the color of our eyes or
result in crumpled wings. The second Nobel Prize went to someone who
used X-rays to produce all kinds of freaky fruit flies. The other prizes have
been presented for learning about a wide range of topics: namely embryonic
development, immunity, the olfactory system, and circadian rhythm. I can
understand how we might throw some light on understanding the olfactory
system. We do have a keen sense of smell when it comes to finding rotting
fruit. But it’s hard to figure out how we helped scientists learn about the

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And the Winner Is . . .


effects of light and darkness. You’d think that a fly, who lives for but a
few weeks, must surely regard a day as a much longer span of time than a
human, who lives for years.

As well as studying our genes, scientists have made pretty colored
pictures of our brains. So it’s clear that their interest in the noble fruit fly
as an experimental animal goes far beyond the fact that we have a speedy
life cycle and are easy to feed and rear. We tiny flies have far more in
common with humans than you’d expect. Even though they have 23 pairs
of chromosomes and we have only four pairs, humans and fruit flies share
60% of their DNA. This has led to humans mapping all our genes and we are
now important in a new branch of science called genetic engineering. That’s
where scientists move genes from one species to another. This has turned
out to be important in an amazing range of different ways—everything from
curing genetic disorders to giving tomatoes a longer shelf life.

I wonder how long it will be before humans borrow some of the 40%
of the DNA that they don’t have in common with Drosophila. With a little
genetic engineering they could have transparent wings like ours and no
longer need to be rooted to the earth. They would surely be far more stable
walking about on six legs instead of balancing on two. Then they could join
the insect world and be part of the most successful evolutionary experiment
ever!

In the words of the poet William Blake in 1704:
Am not I

A fly like thee?
Or art not thou
A man like me?

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