Word of the day: Exuviate
(The word of the day is a random word on a random page of the Torre-Bueno Glossary of Entomology)
Exuviate, to undergo ecdysis; see moulting
Watch out, that caterpillar is about to exuviate!
A variation of the word is exuviation, another word for ecdysis.
Apparently there are a lot of ways to describe the fact that immature insects go through molts in order to grow.
The resulting cast-off skins are called exuviae.
There are also related exuvial droplets and fluid to aid in the molting process, exuvial glands, and exuvial space (the space between the new and old skins during molting).
I dug through my photos and found this cutie, Acronicta afflicta, next to his exuviae. Most caterpillars build a molting mat out of silk, produced by silk glands on their head, that they can grab onto. They dig their little crochet hooks (found on the prolegs) into the silk and use that grip as leverage to get out of their old skin. If you disturb them during this process you may accidentally rip them apart (they have a strong grip!) or otherwise disrupt the molting process. This gets to be tricky when we are rearing lots of caterpillars and need to transfer them to new foliage, so we often cut out the small piece of leaf they are on and transfer them that way.