Eastern Tiger Swallowtail

Place name abbreviations: MPEA – Middle Patuxent Environment Area; PRSP – Patuxent River State Park; PVSP – Patapsco River Valley State Park.

Click on the common name to obtain additional information from the Butterflies and Moths of North America web page and the following common name for additional information from USGS web page. BugGuide is another web resource.

Legend:

The Eastern Tiger Swallowtail has a dark morph or form that appears only in the female. The females of both forms have much more blue scaling on the upperside hindwing.

The first photo shows a side-by-side comparison of a dark form female (left) with yellow female (right).  You can see that the lower wing iridescent blue is prominent on both butterflies.

The second photo shows a male yellow Eastern Tiger Swallowtail (left) with a female dark individual (right).  You can clearly see that the blue scaling on the hindwing is considerably less on the male.

The phenograms show the maximum number of individual butterflies of this species seen in the first eight years of the Howard County Butterfly Survey. From these graphs, one can see the number of broods of each species, when they are active, and the relative abundance of the species in each brood. The observed early and late dates are shown below The graphs can be used to anticipate the first sighting of a given species in the year and can help with identification.

Early: 4/1/2016 Late: 10/15/2020