Important update: alert reader Alex F. wrote to tell me that I got it wrong! These are really Black Swallowtail larvae (Papilio polyxenes). Thanks Alex! Corrected 4/13/07. He goes on to add: “While they do smell foul if you handle them, they are by no means poisonous. Actually, being that Monarchs feed primarily on Milkweed, they are far more poisonous than Black Swallowtails.” Good to know.
I was on my way to cut some parsley and make a nice tabouli. I reached down and stopped short. I was infested with a plague of Monarch caterpillars. As pests go, these are stylish. But they still ate my crop, and they smell bad when you pick them up, and they are poisonous.
In the end, I just let them munch. The kids got a kick out of seeing them. we counted thirty. Some pioneering caterpillars were striking out in search of more chow because the parsley was utterly stripped. I’m sure very few of these made it. If we had some milkweed around I’d have moved them onto it. but I kind of held a grudge on them for messing with my tabouli.
elegant but uninvited aposematic dinner guest
he brought his crew with him
Clearly they also prefer the leaves to the stems. I’ve never run across a batch of them like this, and we used to grow milkweed when I was a kid just to attract the monarchs.