Insect Camouflage
Judi Manning
Insects are a large part of the food consumed by other animals.
Many insects disguise themselves as something they are not for
protection and survival. Some use camouflage comprised of colors
and patterns to blend in. Others display warning colors to scare
off predators.
Mantids (praying mantis) vary greatly in shape, hue and pattern.
There are four species found in the U.S.; one is native; one is
European and two are Oriental. The latter three were accidentally
introduced and later colonized by farmers as natural pest
control. However, they do not know a good insect from a bad
insect and destroy valuable fruit pollinators. Some tropical
mantids have bodies flattened and shaped like leaves. Some
resemble bird droppings, which attract filth-loving flies. Some
simulate flowers (rose-leaf mantids of India) with the legs and
thorax shaped like leaves. This illusion attracts nectar-eating
insects to their death.
Insects depending on camouflage stay in one position for long
periods of time. A bird following his dinner, the beautiful
Indian dead-leaf butterfly, approaches a bush and dinner
completely disappears. When the butterfly closes its wings and
even to experts, it looks like a dead leaf when it is in its
resting state.
Next in line with the best camouflage are moths. Their wing
colors and markings allow them to blend in with their resting
places. They also spread their wings flat sideways and cast
practically no shadow. They appear to merge into the bark.
One hundred years ago, the dark phase of the peppered moth was
sought by collectors in the British Isles because it was so rare.
Over the years, soot began to pour into the atmosphere in
conjunction with the rapid industrial growth. The resting places
of these moths grew dark and the light phase moths became easy
targets for birds. The dark moths began to survive, reproduce and
multiple. Now the light colored form of the moth is hardly seen.
This is an excellent example of how environmental changes and
pressures favor one variant of a species.
The caterpillar we know as an "inch worm" is also a
master of disguise when it imitates a twig. It grasps the stem it
is perched on with its hind-most prolegs and stiffly stretches
its body into the air at an angle that resembles a stem. It
remains motionless for long periods of time.
In contrast to the use of camouflage for survival, there are the
"good tasting" insects that resemble other "evil
tasting" insects. Bold patterns advertise that it is a
protected insect.
Ref:
Insect Masquerades, Hilda Simon, The Viking Press
Copyright © 1997 Owashtanong Islands Audubon Society. All rights reserved.
