I went down stairs a few moments ago and saw a smallish black thing writhing on the floor. ??what?? A dying mouse? A bat? No, on closer inspection, I see it is a black swallowtail butterfly, in its "birthing" throes. You know how crippled and vulnerable they look when they first come out of their pupae. But what was it doing in my basement? It's too early for them outside, so maybe it hitched a ride inside on one of my houseplants? And then time and warm temps inside made it hatch out.
I didn't know what else to do with it, and didn't think it would survive long in the basement. Maybe the wrong thing to do, but I put it out in the garden in the parsley. It is not particularly warm today, but not freezing. Supposed to be warm the next few days. But, still...maybe I should have kept it in? Should I go out and bring it back in? Give it some sugar water? feed it to the chickens?
Your guess is almost assuredly correct. It's happened to me many times. Eastern blacks make two generations a year one pupates in the summer and becomes and adult in fall and one pupates in fall, overwinters and emerges in the spring. If they are still pupae, you can tell the difference (summer pupae are green, fall are brown).
As for what to do about it, that may be a little more complicated. It was never an issue for me, since my early risers always ended up showing up in January, far too early to make it to spring. For them I usually tried to do the humane thing and gave them to a student in the entomology department (on the grounds that the chemical euthanasia they use is probably a less painful way to go than freezing to death or starvation). but at this point in the year, I honestly don't know. I DID have one show up late enough I could let it go outside. It did fly away, but I have no clue as to how if fared after that.
if it was struggling on the floor, there also might be some question as to it's long term heath. Butterflies need to stay in a hanging or vertical position after emerging to allow gravity to help pump the blood into their wings before they dry and harden. If they are flat upon the ground, the wings won't form the right way, and the butterfly will be crippled and rendered flightless (It happened to me, the first time I did Mourning Cloaks)
By now whatever I done is done, I'd say. If the butterfly was formed correctly it has probably flown away already. If it is crippled there's not much you can do. You CAN give it some sugar water, but butterflies don't live that long anyway so you have to leave it to yourself if you are helping it or just prolonging it's suffering.
And definitely DO NOT give it to the chickens. Eastern Black Swallowtails have chemicals in their bodies that make them VERY distasteful (verging on mildly poisonous) to animals.
I also will point out that, eastern blacks are the adults of parsley worms, so you ay have just shot your parsley crop. Your probably alright only one can't lay eggs (well actually it can, but the eggs will be unfertilized and sterile. But if another Eastern Black showed up while it was there.....you may have to keep your eyes peeled for the eggs (tiny round, yellow) and the worms (they change dramatically in appearance from instar to instar, so just look those up)
