The Tale of the Black Swallowtail
By Paul James
I love parsley, especially the flat-leaf, Italian variety. I use it more often than any herb I grow. But lately, my parsley crop has suffered, not because of something I did or didn’t do, but because it’s being consumed by the larvae of numerous black swallowtail butterflies. And I couldn’t be happier about it. After all, I can replace the parsley, but I can’t replace the swallowtails.
The black swallowtail butterfly is Oklahoma’s state insect. Has been since 1996. It’s not the only swallowtail that calls Oklahoma home (eight different species have been recorded), but it is one of the largest and most beautiful, with a wingspan of three to four inches. Of course, it doesn’t get the attention that the monarch butterfly does, but then unlike the monarch, it isn’t threatened or endangered.
Papilio polyxenes (that’s its scientific name) has two generations a year. After overwintering in their chrysalises, the first group emerges between late April and June, at which point mating begins. The females then lay eggs on the leaves of various plants (my parsley included). The eggs hatch in three to five days, develop into a caterpillar with an enormous appetite, then pupate for nine or ten days. The second group then emerges in late summer, and their eggs become the first generation the following spring.
The caterpillar undergoes dramatic changes between hatching and pupating. It starts out mostly black with a white saddle. As it grows, it develops reddish orange spikes on its body. The white band soon disappears, and the caterpillar develops its familiar green and black bands with yellow spots. It also develops an osmeterium, which is a bright orange, two-pronged fork behind its head. When disturbed, the caterpillar pops out the osmeterium, through which it releases an unpleasant smell (think rotten cheese) to ward off predators.
The black swallowtail caterpillar feeds on many different plants, including Queen Anne’s lace (a pretty but rampant weed), carrots, celery, dill, fennel, parsley, and rue. The butterfly eats nectar from bee balms, coneflowers, clover, milkweed, thistles (also weedy), Pentas, Phlox, and Salvias, just to name a few.
Sadly, adult black swallowtails typically live only 10 to 14 days. That’s reason enough to enjoy them all the more.
Happy gardening, ya’ll.
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