predatory stink bugs hatched 6-11-15

Spined soldier bugs, predatory stink bugs, hatching from eggs

One thing you can say for insects, there is always something going on. Whether an insect undergoes complete or gradual metamorphosis, identifying a species can be tricky. Even simple metamorphosis still requires that an insect molts from one stage to the next, and sometimes the color change between molts is striking. Here is a quick look at some insects and the different appearances they may have.

This year I was able to raise a spined soldier bug, Podisus maculiventris, from an egg through to the adult. Although its body form was definitely that of a stink bug (Pentatomidae family), the color changes went from very colorful to a drab brown at the finish. Now I know all the instars, so in the future identifying this stink bug will be easy.

predatory stink bug new instar

spined soldier bug after 2nd molt

predatory stink bug later nymph

4th molt

spined soldier bug 2014

Spined soldier bug adult


Caterpillars can also be hard to identify as they go through the larval stages. Most will have distinguishing forms or marks by the third instar, but sometimes the overall change may be more subtle until the penultimate instar is reached. Most identification aids show the final instar, even though a radical changes may occur throughout the larval stage. If possible, rear any caterpillars to the final instar to be certain of identification. Host plants may or may not be that helpful as some caterpillars can be found on many host plants. Others, like the double-toothed prominent, are found only on one host plant, in this case, elm. The cecropia, on the other hand, I have personally found on a variety of plants- from black cherry, alder, buckthorn and apple, just to name a few.

cecropia and its egg shell 6-25-11 on cherry

Cecropia caterpillar beside its egg

cecropia 2nd instar

Cecropia 2nd instar

cecropia 4th instar 7-12-11

Cecropia 4th instar

double toothed me and my shadow week old cat

Double toothed prominent early instar

double toothed prominent raised from eggs 2011Ii

Double toothed prominent late instar

orange striped

Orange-striped oakworms very early instar. Note black horns are present even early on.

orange striper II

Orange-striped oakworm final instar

The orange-striped oakworms can be serious pests of oaks, especially in eastern Connecticut. Eggs are laid in large rafts near the bottom  of many oak species and feeding results in severe defoliation. Note the black horns, though, which are present on caterpillars in all larval stages. The horns plus the host plant are valuable aids in identifying this pest.


Pamm Cooper                              All photos copyright 2016 Pamm Cooper