I found this caterpillar on my redbud tree august 18, 2006 in Callaway county, Missouri while filling my hummingbird feeders. I didn’t think much about it except that I had never seen one like it before. I forgot all about it and the next day when I reached for one of my feeders the back of my hand started stinging. I looked to see what I came into contact with and there was that same caterpillar. I took some pictures of it and put it back in the tree.(Away from my feeders). From what I could find, I think it might be a Stinging Rose Caterpillar. Am I correct? All the other pictures I have seen has an orange body. By the way your website is GREAT!………
You are correct. This is a Stinging Rose Caterpillar, Parasa indetermina. Bugguide lists redbud as a host plant as well as apple, cottonwood, dogwood, hickory, oak, sycamore and the namesake rose. There is some degree of color variation in the caterpillar. Some lack orange entirely, some being mostly orange, and some somewhere in-between like yours.