For many years I’ve noticed colorful little caterpillars that live individually in silken retreats on the surface of leaves of poison ivy. At a recent BugGuide gathering, a photo of one of these caterpillars was shown and I realized we still didn’t know what these were. I resolved then to rear a few to try and arrive at an identification. There’s plenty of poison ivy near my home, so I didn’t anticipate much trouble finding a few.
Here’s the first one I found. The white area just behind the head is atypical. The caterpillar is smaller than usual, so it might be an early instar. It could also represent some sort of injury.