Well, it seems that I’ll be doing two butterfly diaries this year after all.
The Eastern Black Swallowtail (Papilio polyxenes), which I shall henceforth refer to as the EBS, favours as its larval host plants various members of the Apiaceae/Umbelliferae family. For most gardeners, this means carrots (including wild carrots, a.k.a. Queen Anne’s Lace, Daucus carota), dill (Anethum graveolens), rue (Ruta graveolens), and parsley (Petroselinum crispum). I’ve always found this rather ironic, because while the EBS is native to eastern North America, none of those plants I just listed is native.
In my garden, the mother EBS are usually attracted to my carrot patch. However, I started my carrots late this year – over a month late – so I figured I wouldn’t get any EBS. Wrong. Apparently a single feathery five-foot-tall dill plant was more noticeable or more desirable (or both) to a mother EBS than two square metres of six-inch-tall carrot plants. (Yes I know I mix measurement systems. Deal.) The caterpillar I found today looks to be two or three days old, and I’ll make the guess of two days.
Interestingly, from a couple experiments in past years, it seems that although the EBS has several host plants, the caterpillars prefer to eat whatever plant they first fed on.
Here’s the little darling, on a bit of dill. At this stage the EBS caterpillar is typical of swallowtail caterpillars on this side of the world: black with a white patch in the centre (called a saddle) and pretty knobby/spiky. The posture is also typical, wth the front segments held in a sort of hump. The overall impression is similar to a bird dropping. In some species, especially the more tropical ones, the caterpillar retains this disguise all the way, but the EBS doesn’t. In a couple of instars it will turn light green with black and yellow markings.
And here it is from today, Day 10. It’s well over an inch long now, and loves its food. It had just finished its last ecdysis, because I found its old face just underneath. I’m not kidding; at the beginning of moult the old face falls off and it walks out of its old skin. The old skin often gets eaten (depending on species), but I suppose the face is too tough, or falls out of reach.
Hmmm…what else…OH YES! The jewelweed (Impatiens capensis) is flowering! I know it takes a special sort of mind to get excited about what is essentially a wild-growing weed, but the fact is I’ve wanted this plant in my garden for years now. And not just a few plants, but for it to maintain as a self-sustaining population (so I don’t have to go tramping through the woods gathering seeds [ethically!] every year, considering it’s an annual). That remains to be seen, but for now I’m thrilled. Thrilled.
And the elderflower wine was delicious.