Page 1 of 5 Wisconsin Butterflies butterflies tiger beetles robber flies Search species Little Glassywing Pompeius verna The Little Glassywing is not a common butterfly in Wisconsin. When the Butterflies of Wisconsin was written in 1970, only two specimens of this species were known from the state. I had not seen this species in central Wisconsin until 2003 when I saw two individuals in Fond du Lac County, two individuals in Marquette County in 2004, and one in 2005 in Buffalo County. Others have seen this species in the more southern and northern counties, so it is likely that it is found throughout the state, but rarely in large numbers. NABA counts for Wisconsin for 2004 and 2005 had only 26 individuals in 36 counts taken in those years. Weekly sightings for Little Glassywing Identifying characteristics This is mainly a dark skipper from both above and below. From below, very fresh individuals appear somewhat reddish brown with a very faint spot band on the hindwing. From above, the female has a large, nearly square, white spot in the middle of the forewing. The male is similar but the large spot is rectangular rather than square. Similar species The female Dun Skipper and the female Northern Broken-Dash are somewhat similar and have been referred to as the three witches by a variety of authors. All three skippers are very dark and if they are all moving around together it is indeed somewhat difficult to distinguish each species. The Dun Skipper is much darker above with light spots usually much smaller and less obvious, especially the subapical white spots on the forewing that are very obvious and conspicuous on the Little Glassywing. The Northern Broken-Dash usually has some lighter, orange coloration on the leading edge of the forewing
Page 2 of 5 and the larger spot in the middle of the forewing is not as large, nor as square as the Little Glassywing and is also orange, especially in fresh individuals. The Little Glassywing, unlike the other two species, has a white area on the antennae just before the antennae clubs. This may not be the easiest to see and if I look at the photos here, only the bottom one really shows this characteristic. Habitat Usually found in moist, open areas near woodland edges. Flight One generation. The first ones are usually seen in the late June and are usually in flight until early August. Abundance This is not a common species in Wisconsin. I have only seen it at five sites and saw seven on one day in 2007, the most that I have ever seen in one day. Early Little Glassywing Sightings Date County Reported by Jun 18, 2006 Marinette Mike Reese Jun 18, 2006 Marinette Mike Reese Jun 25, 2005 Dane David Drexler Jun 29, 2002 Waukesha Bill Barber Jun 30, 2007 Ozaukee NABA count, 12 observers Locations
Page 3 of 5 Skippers Grass-Skippers Female, Northern Kettle Moraine Forest, Fond du Lac Co., WI, July 14, 2003. Female, Northern Kettle Moraine Forest, Fond du Lac Co., WI, July 14, 2003.
Page 4 of 5 Female, Waumandee Creek Farm, Buffalo Co., WI, July 15, 2005. Male, Page Creek Marsh, Marquette Co., WI, July 11, 2004.
Page 5 of 5 Male, Page Creek Marsh, Marquette Co., WI, July 11, 2004. Prairie Haven Farm, Buffalo Co., WI. July 10, 2007. Show lightbox 2009 wisconsinbutterflies.org contact about