I’m pretty sure this is a spicebush swallowtail (Papilio troilus). There are three dark swallowtails that we see somewhat regularly. Most of them are dark form females of the eastern tiger swallowtail (Papilio glaucus). This is, in my experience, the second most common. Then there are the black swallowtails (Papilio polyxenes). They all look pretty similar and they all have a bit of variation in their coloration. Since I’m really not an expert, I could be wrong about this one. I’ll just leave it at that. It’s a pretty butterfly, in any case, and is enjoying the blue lobelia (Lobelia siphilitica ) in our front garden.