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Insects Photography

Old World Swallowtail

Today my brother Ted was here, having come up from Rapid City to work on the communications tower north of my campsite. We were sitting outside visiting when I noticed a different species of swallowtail flying around. At first, I thought it was an Anise Swallowtail. It landed and I got a few photos. Later, I was checking the photos and determined that it was actually an Old World Swallowtail, also referred to as Baird’s Swallowtail, which is the subspecies that occurs in this area. This is a lifer butterfly for me! The Old World Swallowtail is found across Asia, Europe, and western North America, nearly the entire palearctic region. It is the only species of swallowtail in most of Europe. There are over 40 recognized subspecies. Unlike the nearly identical Anise Swallowtail (for which the larval food is plants in the Parsley family), the larvae of the Old World Swallowtail feed on various species of sagebrush and sageworts.

My first clue was the black spot in the orange eye of the hindwing. In an Anise Swallowtail, that black spot is centered. In the Old World Swallowtail, the black spot is on the border.
I got more photos, some showing the underwing and abdomen. The Anise Swallowtail has a mostly black abdomen; the Old World Swallowtail has a yellow abdomen with black stripes. There are other differences too but are more subtle and not as easy to pick out.
A nice frame filler! I surely didn’t expect to get a lifer butterfly out here in the Slim Buttes, but I did.
An Anise Swallowtail from the Black Hills, for comparison.

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