Confusing Dark Swallowtails

When butterflies are flying to and fro in your garden, it can be hard to quickly identify which dark swallowtail you might be seeing: is it the more common Eastern Tiger swallowtail dark form female or something more unusual? If you can get any pictures, it is helpful to have a dorsal view (as if you were looking down on it) and a ventral view (from the side, including the abdomen if possible). In these days of smartphones, sometimes the easier thing is to take a video rather than focus on single shots which might be blurry.

This post was inspired by a post created in 2009 by Louisiana Naturalist about four species of swallowtail butterflies that have dark forms: Spicebush swallowtail, Pipevine swallowtail, Eastern Black swallowtail, and the dark morph of the female Eastern Tiger swallowtail. All of these butterflies are found in Georgia, particularly in my area (metro Atlanta). Southern Georgians may also have the Palamedes swallowtail (not covered here). With the permission of the original blogger, I am making my own version of her blog in case hers should ever disappear. Here is the link to her original blog.

The beauty of Rachel’s post is the ability to see the same view of all four of them at the same time so I will follow her lead on that. Here is the dorsal view of them (and I believe all of these are females).

In the same order, here is the ventral view of all four.

Now that you’ve seen them, let’s discuss which is which and what makes them different. Here is the dorsal side again with identification tips circled.

Upper left is Black swallowtail: look for the black dot inside the larger orange dot. I find this butterfly to be the smallest of the four.

Upper right is Eastern Tiger swallowtail: the upper edges of the wings have white marks that look like dashes and there is a tiny dot circled showing a spot of orange inside a white dot. This butterfly is the largest of the four.

Lower left is Spicebush swallowtail: the light blue edges circled can look like fingertips.

Lower right is the Pipevine swallowtail: overall the wings have less detail, just a soft wash of blue color and white dots but the tails are noticeably blue.

In the same order, here is the ventral side with identification tips:

The first thing I want to point out is the look of the abdomen: notice that 3 of them have dots and one doesn't (Who doesn't have spots? Well, even kids know that a tiger has stripes! You just can't see the stripes on this all back form.)

Upper left is Black swallowtail: there is a double row of orange dots and the row closest to the body has one double set; there is that orange circle with the black dot again; and the abdomen has spots.

Upper right is Eastern Tiger swallowtail: the white marks still look like dashes; there is a single row of orange dots; and the abdomen is solid black (or striped in an intermediate form).

Lower left is Spicebush swallowtail: two rows of orange dots and in the row closest to the body one dot is missing; and the abdomen has spots.

Lower right is the Pipevine swallowtail: a single row of orange dots (some consider it to be in a strong J form); the tail is blue; and the abdomen has spots and often is bluish.

Of course there are also some differences between males and females, particularly for the black swallowtail so I am including an extra picture of the male black swallowtail (dorsal view). In the case of the Eastern tiger swallowtail dark form, occasionally there is an intermediate form that is in between yellow and dark; I am including a photo of what that might look like. The Pipevine and Spicebush male dorsal view can be more vibrant (than the female) so I am including photos of them.

Black swallowtail - male

Intermediate form Eastern Tiger swallowtail

Spicebush swallowtail - male

Pipevine swallowtail - male on left

And finally there is a swallowtail lookalike that is not a swallowtail: the Red-spotted purple. This species looks very much like a swallowtail who lost its tails, but it is not one at all. This species is distinctive in that it rarely nectars on flowers; it likes minerals on the ground and also some rotting fruit. It has red spots on the edges of the upper wings (sometimes they are very faint).

Red-spotted purple butterfly