Last year I saw one of these caterpillars on a carrot plant. So beautiful. Later I found out it is a future black swallowtail butterfly. Recently I saw this guy on a stripped volunteer carrot plant. Then I noticed there were two caterpillars on the same plant.
I chose to leave them alone since the plant was a volunteer anyway. Here’s a closeup of one of the caterpillars.
A few days later I pulled the “carrot” from the dirt and discovered it was actually a wild carrot – Queen Anne’s lace (Daucus carota). So they did me a favor by eating the wild version and not my cultivated carrots.