Page 1 of 5 Wisconsin Butterflies butterflies tiger beetles robber flies Search species Eastern Tiger Swallowtail Papilio glaucus The Eastern Tiger Swallowtail is a very common and conspicuous butterfly of southern Wisconsin. It is replaced farther north with its close relative, the Canadian Tiger Swallowtail. This species and the Canadian used to be considered subspecies and some confusion has resulted because of this. The USGS site currently has grouped the two Wisconsin species together. Historical data will be included when it becomes available. Weekly sightings for Eastern Tiger Swallowtail Identifying characteristics Above: bright yellow with broad black stripes; females are dimorphic, some similar to the males and others are black with extensive blue scaling on the hind wings (photos 3 & 4. Notice that you can see the tiger stripes on the third photo.). Below: similar to the top side, mainly yellow background with bold black stripes; dark females have a shadow of the tiger pattern evident, at least in fresh individuals. Similar species The dark female of this species would most likely be confused with the Pipevine Swallowtail which also has only a single row of spots below but has very distinctive, iridescent blue coloration on the hind wings, and the Spicebush Swallowtail and Black Swallowtail which have two rows of orange spots below. Above the Eastern Tiger Swallowtail black form female has a very thin row of white spots on the upper forewing margin that is easily spotted in the field and is unlike any other black colored swallowtail in Wisconsin. The bottom photo shows a very worn female that has lost most of her tails, but notice that you can still see the white row of light spots on the forewing with which I was able to identify this species in the field. The yellow forms can be confused with the Canadian Tiger
Page 2 of 5 Swallowtail. Eastern Tiger Swallowtails have the following characteristics: 1) the yellow marginal spotband on the front wing below is broken into distinct spots, while in the Canadian these are continuous (unfortunately,some Eastern Tiger Swallowtails do have continuous spots bands); and 2) the broad, black line on the trailing margin of the hind wing is less than half way to the first vein, while in the Canadian it is at least half way to the first vein. Habitat Wooded areas and open areas near woodlands. Flight Two broods; May/June and then in late July/August. Adults can be found on the wing well into August. Abundance Common throughout the southern part of the state. Locations Swallowtails Swallowtails
Page 3 of 5 Muir SNA, Marquette Co., WI. July 25, 1999. Black female, Rocky Run SNA, Columbia Co., WI. August 10, 2005.
Page 4 of 5 Black female, Rocky Run SNA, Columbia Co., WI. August 10, 2005. Same individual as above photo. Rocky Run Creek, Morse Rd., Columbia Co., WI. June 30, 2005.
Page 5 of 5 Bellevue State Park, IA. July 28, 2005. Avon Bottoms, Rock Co., WI. July 30, 2006. Show lightbox 2009 wisconsinbutterflies.org contact about