Watch out when touching hairy caterpillars. Not all of them are harmful, but some can cause an allergic reaction on your skin.
The Oat Eggar (Lasiocampa quercus) caterpillar is one of those that needs to be treated with care. Touching the hair of the caterpillar is somewhat similar to touching nettles. To protect itself from predators, the caterpillar also builds its cocoon using the same hair.
I couldn’t resist testing what happens on my skin after gently rubbing the surface of the cocoon against my wrist. The reaction, a nasty, itchy allergy. The interesting part of the test was that the allergy remained for about 6 weeks, leaving a visible rush and occasional itch. The conclusion? Don’t touch!