Papilio troilus Male Ecloses

One of our spicebush swallowtail (Papilio troilus) pupae has eclosed into a male. Originally found as a larva on spicebush (Lindera benzoin) in Ithaca, New York.

---

Well, this is certainly a big surprise. We had assumed that all of our troilus pupae were in diapause given the time of year and deliberate darkness treatment to counter unnatural indoor photoperiods. We certainly have not been seeing an of the adults in flight or been finding any eggs (or larvae for that matter) for the past few weeks already, so they are clearly already mostly done in the wild. But perhaps it is not too late for them to emerge right now as it is not truly cold yet and won't be for at least another several weeks. . . we will just consider them stragglers. 

Anyway, here is a shot of the pharate pupa with the others. Color doesn't seem to have anything to do with diapause as this one was originally brown.

And here is the pupa up close: 

It eclosed a while later into a spectacular blue laden male.   

For how small the pupa are, both visually in volume and by weight, the adult is not small at all in terms of wing size. For P. zelicaon of the same weight, we suspect that the troilus would win out, which would make sense because that would be the case with rutulus (also Pterorous​). 

Both the forewings and the hindwings are very rounded along the edges, giving it a characteristic troilus look. The tails are uniquely club-shaped, which is not quite the case in other swallowtails or in the female we caught before. The abdomen is also much more heavily marked in yellow compared to the female. The shape of the abdomen is long and skinny and very similar to the tigers, but the clasper is fairly small. 

---

Authors
Brian Liang

---