Yesterday I noticed this little guy crawling around on my parsley. This is the caterpillar of the Black Swallowtail butterfly. Apparently they eat food in the Apiaceae family, of which parsley is a member and upon which the female lays her eggs. He was chowing down on that plant, but I have enough to spare.
I’ve been growing parsley for years and never noticed them before. Soon the caterpillar will form a chrysalis from which a Swallowtail butterfly will emerge in the spring.