Looks like a Datana to me!

Kind of pesky little cats. The red-banded hairstreak also uses Sumac as a host plant.

Susan

Thank you tomato worm! I looked a little further and found several related species of Datana. One has a common name of yellowneck caterpillar, and it feeds on oak and dogwood, among others. I don't see any damage on the oaks, and I sure hope it isn't after the dogwood. :(
Its close cousin is blackneck/sumac caterpillar, and it _only_ feeds on sumac. I hope that's the critter, because there is plenty of sumac to keep it happy. I only found one reference to it using Google, and didn't find a picture.

It was kinda fun this morning when the whole clump was asleep, to thump the sumac and watch them all arch up in unison. Those guys can sure strip a plant!

Yep, I never heard of yellow necks eating sumac, but those are most likely black necks, a very similar species. get close to the group and they wag heads and raise tails. If you ever rear Datana's, they must be collected in small groups as they don't like to be alone. These are very social and gregarious larvae.

That's interesting! I thought I would not try to rear them because I did not know what moth larvae need. I do know they burrow, but I did not know how to keep them over the winter.

Check out the mutant dude with the red head!

I just read all the postings on the caterpillars on sumac -- I found thousands on them and chopped down the sumac. Any other solutions? ARe you all in Oklahoma? I am at the Jersey Shore./Users/margaretbuchholz/Desktop/worms.JPG