black etched prominent Cerura scitiscripta

Caterpillar of the black-etched prominent has highly modified anal prolegs that it can flail to defend itself against predators

 

I love insects. They are amazing.

-Andrea Arnold

 

Many insects never make it to adulthood to complete their life cycles because in the grand scheme of things, they are low on the food chain. Between birds and amphibians, mammals and fellow insects, there is no lack of creatures that rely upon insects as a food source. Insects are not necessarily limpid little defenseless victims of a more sophisticated life form, though. They have strategies for survival. Some use camouflage,  are cryptic in form and color, veil themselves with material, have weapons they use when threatened or they may simply hide. 

rose-hooktip-moth Oreta rosea-cryptic

Rose hooktip moth hidden by day by blending in on a leaf

P1270059

Pine sphinx caterpillars blend in with the green and white striped needles of white pine

One of the ways insects can hide in plain sight is by coloration, body form and feeding techniques. Spring caterpillars are often light green and feed on new leaves of similar color. Caterpillars that feed on mature foliage often have colorations or body forms that imitate the dead leaf spots and edges that occur later in the year.

cocoon structure of caddisfly- possibly Climacia areolaris

Spongillafly pupates inside this structure it made

Warning coloration protects many insects from being eaten, especially bright reds and oranges. Also, insects may have warts that sport hairs that repel some birds and other predators. One such insect having both is the red-humped caterpillar.

red hump caterpillar Pamm Cooper photo

Red- humped caterpillars Schizura concinna have warning colors and warts with hairs that detect air movement

Some caterpillars feed along leaf edges and appear to be part of the leaf itself. Careful scrutiny will reveal the ruse. Two of the prominent caterpillars, the Wavy- lined Heterocampa and the Lace-capped caterpillar are just two examples of this behavior.

wavy-lined-heteocampa-2-on-leaf-edge

Wavy-lined Heterocampa caterpillar hides in plain site feeding along the edge of a sweet birch leaf. It blends in also with cryptic coloration.

Walking sticks are a good example of cryptic coloration and mimicry. Both the insect’s shape and color allow it to blend in with leaf veins and twigs  so that unless they move or cast a shadow, they are very difficult to see.

walking stick 6-29-14

Early instar walking stick blends in with leaf vein color

Camouflage loopers are small caterpillars that are found on the flowers of composites. They take petals from the plant’s flowers and “glue“ them on their body. They blend in so well that the only evidence of their presence will be that the flowers seems to be deformed.

camouflaged looper plus tiny looper Belding

Camouflage looper sitting atop a flower head from which it has cut and pasted the flower petals upon its body

Caterpillars like woolly bears, Ios, slug moths and some tussocks have defense mechanisms that utilize urticating hairs or venomous barbs to ward off potential predators. Handling these caterpillars may prove a painful experience for some people. Especially to be avoided are the saddleback slug moth and the spiny oak slug caterpillars, which are very small but able to inflict severe pain or a burning sensation that may  last for several hours or even a few days. Use caution around any caterpillar having barbs, hairs or spines.

small saddleback

Tiny saddleback caterpillar has both urticating spines and coloration similar to the host plant leaf for defense

Another means by which insects can protect themselves is by mimicry. Many flies have coloration and markings that are very similar to wasps and bees, especially syrphid flies. These flies can also feed on the pollen of many of the plants that bees and wasps also visit. Birds will tend to avoid any insect that may have the potential to sting, so these bee mimics need not worry as they go about their everyday work acquiring pollen.

syrphid fly

This syrphid fly resembles a wasp and birds will leave it alone

Many insects use leaf shelters as a means of hiding from predators by day and then feed at night. They may tie leaves together with silk or fold a leaf. The caterpillar of the  spicebush swallowtail and the poplar tent caterpillars do this. Stink bugs routinely use leaf shelters abandoned by other insects.

spicebush ready to eat

Spicebush swallowtail caterpillars hide by day in a leaf folded lengthwise

red admiral

Chrysalis of the red admiral butterfly is made inside a leaf shelter where it was protected as a caterpillar

Some insects feed as immatures inside plants such as gall makers, borers, leafminers and others. Safely inside plant tissue, success rates of surviving to a mature adult are very high.

Pine Cone Willow Gall, caused by a gall midge, Rhobdophaga strobiloides. 9-16-19

Pine cone willow gall houses a midge larva, Rhobdophaga strobiloides

thief weevil

Thief weevil female laid an egg inside two a tightly rolled structures they made by cutting the leaf edge lengthwise while still remaining attached to the pedicel. Larva will feed safely inside on the leaf tissue.

potter wasp pot

A potter female wasp made this small clay pot and inserted food and its egg inside. Larva will be safe inside.

The larvae of tortoise beetles, 3-lined potato beetles and the infamous lily leaf beetle pile their frass on their bodies to escape predators.  Lacewing larva use their molted skins and other detritus to cover their body in a similar way. They can be found especially on white oak leaves in late summer appearing like a small, light tan, fuzzy pile moving across a leaf.

tortoise beetle larva waving frass hood

Tortoise beetle larva raises a “hood” made of frass when disturbed

This is only a brief look at some ways insects survive or attempt to survive in the world. There are many other ways and means by which insects employ subterfuge and other strategies that could fill a book, but this is simply a leaf through…

 

Pamm Cooper