Caterpillars on the Parsley

Earlier this summer I started growing butterfly weed, Asclepius tuberosa, from seeds. It's an orange-flowering milkweed that attracts butterflies. While I was in the hardware store picking up peat pots to sprout the seeds I bought a cute herb garden on impulse and started those seeds, too, including parsley. The butterfly weed grew great and I've planted it outside and am waiting for flowers. The parsley was growing so slowly in the window greenhouse that I thought it would be helped by time outdoors, so I put it outside. After a couple of days, I noticed there were little black caterpillars on it! Three caterpillars. 

This caterpillar is tiny, about one quarter of an inch long. It has spikes and a white saddlebag marking in the middle. I think it will grow up to be a black swallowtail butterfly. People say that this color pattern is protective camouflage that disguises the caterpillars as bird droppings. Click to enlarge. 

Here is the problem. My parsley plant is puny. Sure it can support baby caterpillars, but they will soon be big enough to eat the whole thing. And what then? Some caterpillars are very picky about what they eat. Black swallowtails want greenery in the carrot family: carrot, queen Anne's lace, dill, parsley, and all. They aren't nicknamed "parsley worms" for nothing. My little parsley plant is the only acceptable food in sight. 

So I have moved the caterpillars into protective custody. Here's their new  habitat, which I'm keeping clean, covered, and supplied with fresh parsley from the market. Can you see one on top of the foliage? Caterpillars grow in abrupt stages, called instars, emerging from shed skins bigger and, for these, with some beautiful color pattern changes. I'll photograph as it happens and hopefully we'll see these parsley worms to adulthood.

I was aiming to attract butterflies to my garden. Now I'm hoping to have some in my kitchen. :-)