My caterpillar season is starting to gain momentum. Caterpillars are hatching, eating, growing, pooping. Getting eggs in the mail from collaborators. Running around campus to collect plants. And some of the caterpillars from my Texas trip are approaching pupation.

I was somewhat in denial of this fact until I saw the size of this guy.

Acronicta sp. (afflicta?)

That is a FAT caterpillar! I’d never seen an Acronicta caterpillar look quite so much like it’s going to pop. It also wasn’t in a terribly good mood.

This body language is fairly clear.

Today I found out why. I checked on Mr. Angry Sausage Caterpillar and it looked a bit… different.

Have we met?

The bright reddish orange coloration and jet-black head were an impressive change. I have only seen this sort of change in one other species, Acronicta lobeliae, which also gains a black head and darker coloration before digging a pupal chamber.

I’m waiting!

I realized this caterpillar had stopped feeding and was ready to pupate. Poor thing was waiting for the right substrate!

I put a piece of soft, spongy wood into the container, since most Acronicta pupate in wood. It found the wood within minutes, and within an hour had chewed a tunnel into the wood. It’s currently sealed up, where it will remain for a couple months until it is ready to emerge as an adult.

I’m still not entirely sure which species this is. It was collected in Fort Davis, Texas. My guesses are either A. afflicta or A. brumosa. What do you think?