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

Io female 9-20-15 II

Female Io moth has prominent eyespots to scare birds and other predators

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. There are no lack of creatures that rely upon insects for food, both for themselves, and perhaps their young as well.

rose hooktip moth cryptic

Rose hook tip moth is hard to see resting on leaf in the woods

But insects are not necessarily limpid little defenseless victims of a more sophisticated life form. They have strategies to overcome the odds of becoming dinner for something else. Some use camouflage, others are cryptic in manner and color while some have mastered the technique of veiling themselves with material. Others simply hang out  in plain sight, protected by urticating spines or irritating hairs.

tortoise larva II

Clavate tortoise beetle larva carries excrement and debris over its back by means of a forked appendage on the rear of its abdomen

The wavy- lined heterocampa feeds and rests along leaf edges and manages to blend in to avoid many predators. Other caterpillars are armed with urticating spines or irritating hairs that release toxins when touched. Lesson learned after contact with these guys.

wavy- lined heteocampa 2 on leaf edge

a wavy- lined heterocampa caterpillar is feeding along the lower right of the leaf edge

Camouflage loopers are small caterpillars that are found on 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. Other loopers are twig mimics and hide in plain sight.

camo looper

A camouflage looper (center, top) is aptly named, attaching pieces of flower petals to its body to hide on goldenrod flowers

Io caterpillars- two instars Photo Pamm Cooper

Io moth caterpillars are covered with spines that give a painful sting when touched

Some insects form leaf shelters which they hide inside to avoid discovery. Stink bugs often use abandoned shelters of other insects, while the spicebush swallowtail caterpillar makes its own by folding a leaf lengthwise.

spicebush final instar photo copyright Pamm Cooper

The caterpillar of the spicebush swallowtail not only has huge eye spots, but it hides inside a folded leaf on its host plant

 

There are insects that have eye spots that may help scare off predators like birds and small animals. The eyed click beetle, female Io moth and the spicebush swallowtail caterpillar are a few examples of insects that use eyespots as a threat defense. Some prominent caterpillars, like the white furcula and the black-etched prominent have modified anal prolegs that are more like tails. When disturbed, they flail these around and may scare off parasitic insects and other threats. The small filament bearer looper has a pair of pale-tipped tentacles on its dorsum it can flail about when alarmed.

black etched

Black- etched prominent caterpillar flailing modified anal prolegs

eyed click beetle Ruby Fenton picnic table 6-15-14

Eyed click beetle

Thyridopteryx ephemeraeformis bagworms spin a silk bag to which they attach host plant leaf material-whether pieces of leaves or needles. They remain safely inside until night comes, which is when they feed. Hard to detect when host plant material is fresh, during the winter look for the dangling brown bags. Remove as you see fit.

bagworm case on small oak sapling mt rd power line january 2019 Pamm Cooper photo II

Pieces of oak leaves were stuck on the silken bag of the Thyridopteryx ephemeraeformis eastern bagworm.

Walking sticks are very cryptic in coloring, often blending in with leaf veins of host plants. Unless they move, they are very difficult to discover. Some loopers have coloring and markings that are very similar to their host plants, one being the oak besma caterpillar.

walking stick blending in on filbert July 1, 2014

Walking stick blends in with the leaf veins of native filbert

Viceroy and red- spotted purple butterfly early instar caterpillars eat leaf tips first and then rest on the exposed midrib where they are hard to see. Later instars hide in plain sight on upper sides of leaves, avoiding detection by resembling bird droppings and remaining stationary by day.

VICEROY CATERPILLAR resting along midrib of eaten leaf

Viceroy caterpillar on mid rib of eaten leaf tip

 

Some insect larvae feed within plants where they escape predation. Gall- forming insects, leaf miners, and borers are some examples of internal feeders. The female leaf rolling (or thief) weevil chews along oak leaves and rolls the flap tightly. It remains attached to the leaf, so the piece stays alive as the weevil larva feeds safely from inside this structure called a nidus.

Grape Tube Gallmaker galls on a wild grape leaf

Grape tube maker galls on wild grape

 

There are many other ways that insects can survive predation including cryptic coloring, hiding in leaf litter, and simply dropping from plants when alarmed. They may be small, but they are well equipped for their struggle to survive on planet earth.

oak besma twig mimic

Oak besma looper on right, oak twig of host plant on left

 

Pamm Cooper

 

 

 

 

Program at the Museum of Natural History UConn campus on July 25, 2015 1- 3:00 p.m.  (more…)