Letters from the Insect World

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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 19
The Grave Digger 23
Flying High 27
Digging up the Dirt 31
Homes made to order 35
The Life of a Workaholic 39
The Silk Road 43
Lighting up the Night 47
Masters of the Air 51
The First Farmers 55
Back from Extinction 59
Walking on Water 63
The Magical Insect 67
A Sullied Reputation 71
The Celebrated Stonemason 75
And the Winner is . . . 79
Glossary 82

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Letters from the Insect World

A Letter from the Author

Dear Reader,

Have you ever thought about studying the lives of wild animals? Maybe
you’ve pictured yourself photographing elephants in the African savannah
or chasing after sloths in the tropical rainforests of Brazil, but those dreams
aren’t likely to come true right away. There are, however, animals as close
as your own backyard that lead interesting lives. They’re not nearly as big as
elephants and they move much faster than sloths. They belong to the most
numerous and successful group of animals on the planet.

Meet the humble insect!
An insect is defined by numbers: six legs, three body parts, two antennae
and one exoskeleton. Most have four wings, some have two. Once you get to
know insects, you’ll encounter characters equal to any in a science fiction
movie. There are the bad guys and the good guys. The bad guys cover a
wide range. Bark beetles, each no bigger than a grain of rice, can wipe out
a forest. Swarming locusts can lay waste to a field of corn in a matter of
minutes. Termites can gradually destroy a house.
The good guys include the bees, flies, beetles, butterflies and moths
that pollinate plants. We wouldn’t be here without them. There are also the
garbage collectors and recycling agents like yellow jackets, flies and dung
beetles. Insects are an important part of the web of life, providing food for
birds and fish, and even for other insects. Twenty thousand small farms
in Thailand raise crickets for human food. The idea of eating bugs hasn’t
caught on in most other countries, but some day it will. They’re a good

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A Letter from the Author

source of protein.
Insects have been around far longer than we have and they vastly

outnumber us. It’s estimated that there are more than 200 million insects
for every human on earth! In the United States, around 91,000 species
have been given names and at least as many new species are waiting to be
discovered. Like all living things, they’ve been given names in Latin. The
honeybee is known in scientific circles as Apis mellifera. Apis means bee
and mellifera means honey bearing. The first part of the name is the genus
and belongs to insects that closely resemble one another. The second part
identifies an insect’s specific name. Bees, along with ants and wasps and
several other insects are in the order Hymenoptera. An order is a bigger
group that shares things in common. Insects in the order Hymenoptera
all have thin waists, four membranous wings, and go through complete
metamorphosis.

The person who assigns a name to an insect is known as a taxonomist.
With all those insects still waiting to be discovered and named a taxonomist
has good job security. But an insect is more than just a name, so I invited
some clever insects to tell you their own life stories.

Read on!
Margaret Anderson

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 use

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Letters from the Insect World

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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Flying High

Flying High

I have grown old and my wings are tattered
but I still have a few more eggs to lay, so I scan the
sunlit meadow for the familiar shape of milkweed
leaves. No other plant will do. I finally spot a likely
contender and flutter down, confirming that it is
indeed the plant I’m looking for by tasting it with my feet.

I am a monarch butterfly, a member of the order Lepidoptera, which
gets its name from the Greek words lepis for scale and ptera for wings.
Scaly wings. A lot of my scales have rubbed off by now, but I am still easily
recognized by the dramatic pattern of black veins on my orange wings.
Those colors are my protection. The milkweed plant that I hungrily ate
while I was a caterpillar contained chemicals called cardenolides. I am
able to sequester the bitter-tasting poisons in my body. They do me no
harm, but the young bird that eats a monarch isn’t so lucky. It ends up with
a severe attack of vomiting. From then on it shies away from anything with
orange and black wings. Though the sad fact is that a lot of my brothers and
sisters are sacrificed to teach those young birds a lesson.

As I deposit an egg on the underside of a tender leaf, I find myself
thinking that my great, great grandmother may have laid her last eggs in
this very meadow in northern Mexico. When those eggs hatched and the
hungry caterpillars eventually turned into adults, they became part of the
northbound generation, guided by their search for milkweed plants as they
followed the wave of unfolding blossoms and longer daylight hours.

And so it was with the next generation and the next, and the next after

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Letters from the Insect World

that, until the butterflies migrated all the way to the Canadian border, where
I emerged from a jewel-like chrysalis last September just as the leaves were
changing color. The nights were growing colder and the summer flowers
had faded. Other insects were preparing to ride out the winter months in
various stages—as eggs or grubs or pupae or as adults—but even while I
waited for my wings to expand to their full size, I knew that I had a different
destiny. I was going to fly south for the winter, following the route that my
great, great, grandparents traveled the year before with nothing more than
the position of the sun in the sky and the magnetic pull of the earth to show
them the way. I quivered with excitement at the thought of the challenges
that lay ahead.

As soon as my wings were strong enough I took to the air, soaring
upwards and pointing my body to the south. Catching an updraft I
flattened my wings and let the air carry me forward. It was peaceful floating
along, belonging to neither the earth below nor to the sky above. When the
sun began to dip toward the west I returned to the earth and rested that
night in a tree until daylight returned. The following day I saw a few other
monarchs catching the updrafts. In the late afternoon we all returned to
earth and flapped our way over a field of flowers. Before we found a roost
for the night, we filled our bodies with the restoring energy of nectar.

As we travelled further south, our small cohort of butterflies grew.
Although none of us had made the journey before, I felt safer now that I
had found so many companions. Our dancing cloud was made up of both
males and females, but we had no thought of mating. That would come
later. First we must answer the call to fly south.

Toward the end of the fourth week, our confidence was shaken when
the weather changed. We were grounded by rain and a strong wind from
the southwest. All we could do was cluster in a conifer tree and wait for the
weather to improve. There was no point in using our stored energy to battle
the wind. We’d need that energy to see us through the winter months. So
we waited.

Perhaps it was the return of sunshine and a breeze pushing us south,

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Flying High

or perhaps it was the feeling of safety in numbers, but soon after we were
on our way again, I got careless. By now we were used to humans watching
us with expressions of wonder as we flooded fields and gardens in our early
evening search for nectar. So I continued to hover over a bank of flowers
while a woman came cautiously toward me. I didn’t notice that she carried
a net until I was swooped up and found myself trapped. With what sounded
like a squeal of triumph, she reached into the net and pinned my wings
together. I wanted to struggle but this would only rub off some scales. My
wings needed to be strong. I still had a long way to go . . . unless this was
where my journey ended.

The woman had gentle hands. While holding me still, she pressed a
small round label onto my hind wing. She held me for a little longer, and
then she let me go, launching me into the air, saying, “Good luck! I do hope
someone finds you!” For a moment I wobbled, but by the time I reached
the roosting tree, I had recovered my balance although the patch was still
an irritant. I didn’t want to wear a label. And I most certainly didn’t want
some human to find me.

Two weeks later, we changed direction, turning westward and then
answering some inborn call we turned south again. The oyamel firs were
waiting. They are also known as sacred trees because their tips point toward
the sky like praying hands.

It was early November when we reached El Rosario in Mexico. By now
there were so many of us that we covered the sky like a blustery rain cloud.
Already the branches of the firs were bending under the weight of roosting
butterflies. I thrust my way into a mass of insects clustered on a tall, straight
trunk and felt reassured by the warmth of all those bodies. I had found
my winter home. From time to time, the sun slanting down through the
treetops warmed me enough to allow me to flutter off in search of water.
The rest of the time I was dormant, living off the food reserves in my body,
while the other butterflies, packed closed together around me, kept me
warm during the night. The living tree trunk also fended of the cold.

Before we knew it, the spring awakening arrived. Imagine a snow

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Letters from the Insect World

flurry of a million—no ten million—golden flakes dancing in the sunshine.
Crowds of people appeared from nowhere, standing there with open
mouths, gazing upwards, mesmerized by the cloud of butterflies. I soared
higher in the sky in case one of them was that someone the woman had
hoped would find me. I still had her label clinging to my wing.

Now that springtime had reached our mountain home I knew that the
milkweed plants in the valley to the north were waiting. It was time to mate
and then lay eggs to prepare for the northbound generation.

So here I am, looking back on my adventurous life as I lay my last few
eggs in this lonely meadow. When I finally flutter to the ground, I feel secure
that the someone is not going to find my tag. And if they did, what would it
tell them? Those humans want science and a number glued to our fragile
wings to explain how we can fly thousands of miles to the oyamel sanctuary
in the mountains of Mexico just as our great, great, grandparents did before
us. But even I, who was a part of that wondrous journey, can’t provide them
with the answer. Don’t they know that science can’t explain a miracle?

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Letters from the Insect World

Glossary

Bioindicator: an organism that indicates the ecosystem’s health
Bioluminescence: production of light by a living organism
Catalyst: a substance that speeds up a chemical reaction without being changed
Cerci: small appendages occurring in pairs
Chrysalis: the stage during which a moth or butterfly changes to an adult
Cocoon: the envelope that protects the pupa
Elytra: the hard wings covering the hind wings of beetles
Exoskeleton: an outside skeleton usually made of chitin
Inquilines: an insect that lives in the dwelling place of another insect species
Instar: the growth stage between two molts
Labium: the lower lip of an insect
Metamorphosis: the process of changing from an immature insect to an adult
Nymph: the larval stage of some aquatic insects
Ocelli: single lens eyes used to detect movement

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Glossary

Ootheca: an egg case
Ovipositor: a tubular organ an insect uses for laying eggs
Pheromone: a chemical that affects the behavior of other members of its species
Pupa (plural, pupae): the resting stage when the larva changes to an adult
Revoada: a mating dance
Rostrum: a beaklike projection from the head
Stylet: a thin, sucking mouthpart
Subimago: the winger stage of a mayfly before it becomes a mature adult
Symbiosis: the interaction of twu different species benefiting both species
Tarsis: part of an insect’s foot
Thigmotactic: drawn to crevices and cracks
Trophallaxis: mutual exchange of liquids between social insects
Tymbal: a membrane that is part of the sound-producing organ
Xylem: the tissue that conducts water and nutrients up from the root of a plant

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Letters from the Insect World
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