Identifying swallowtail butterflies that are predominately black can be tricky to say the least. Here’s what I go by, and perhaps this will help you too. This is the ventral, or underside, wings up and together side, of a Spicebush Swallowtail (Papilio troilus). Take a look at the two rows of orange spots on the hindwing or posterior wing. On the row nearest the bottom of the butterfly are smaller orange spots that are arranged in a “J” shape. I see seven of them. Are you with me? In the second row, further up the hindwing are larger “mushroom cap shaped” orange spots. Counting in the row, going from the left to the right, where there might have been the third orange spot, there is instead a comet shaped blue smudge. Notice that the very top of the comet smudge there is a hint of orange. That hint of orange is not always on every one of this species. The Spicebush Swallowtail is the only butterfly with this arrangement of orange spots that includes the comet design.

Let’s look at the other side of the butterfly now. This is the topside, wings open side, or the dorsal side of the butterfly. Notice that you’re seeing mostly black with a thin dull white (on this particular one there is a hint of orange too) band of dots and “crescent moon” looking dots on the lower side of the wings. There is also a dusting of blue or blue-green mainly on the hindwings including, in the same color an alignment of comet looking shapes streaming toward the top of the butterfly.

There’s another butterfly that looks a bit like the Spicebush Swallowtail on it’s dorsal side, but it’s not a swallowtail. It’s a Red-spotted Purple (Limenitis arthemis). Take note, it doesn’t have the tails like a swallowtail has. It has small red-orange dots on the outer side of the upper wings. There are no dull white dots along the lower edges of the hind wings, though there is a thin edging along the outer sides of the upper wings and also along the outer and bottom edge of the hind wings. Another thing to consider in comparing these two butterflies: the Red-spotted Purple will grow to have a wing-span of perhaps three and a half inches while the Spicebush Swallowtail will have a wing-span of up to four inches.

I hope this information will help you as you’re out there with the butterflies!