American Dagger Moth Caterpillar

At Afton State Park, Erika and I happened upon this caterpillar of the American Dagger moth. Anything this bright must be an example of aposematic coloration--"be careful, I'm poisonous!" In this case, you'd be correct. Many people develop a nettle-like rash from handling this caterpillar. Seeing as how this critter was grazing on Poison Ivy, the habitat would get you if the caterpillar didn't! The moth is found east of the Rockies, primarily in the United States.