Caterpillar eating Poison Ivy - Arge humeralis. Delaware Wildlife Area, Delaware County, Ohio, USA August 11, 2010. We have observed these caterpillars devour the leaves of poison Ivy stem- It's the first time I've ever seen anything eating Toxicodendron radicans to this extant. Thank you Bug Guide! read more
We did a web search of Poison Ivy Sawfly and found Arge humeralis. There is a matching image on BugGuide. We searched our archives for the image we posted in 2007, and sure enough, it was found on Poison Ivy. read more