Caterpillar identification (hopefuilly!)
I was digging around hoping that I could ID these guys. I am in upstate, NY (finger lakes) and this was taken Sept 13, 2005. They were happily munching on some Pignut Hickory leaves until I disturbed them, and then their butts went up in the air. I tried touching them with a stick, and they have an amazingly strong ability to push on the stick and act quite aggressively. I have never seen these before, and am hoping for an ID. Thinking of going back there and gathering a couple to wee what they become. Probably a dull, grey moth.
Sorry for the delay. This one was tough. These are not caterpillars, but the larva of a wasp relative known as a Sawfly. We actually found it while researching a spider wasp after our caterpillar searching turned up nothing. It appears to be Croesus latitarsus, or something very closely related. We located a link on BugGuide that says they raise their bodies to defend themselves.