Little Glassywing

Pompeius verna

The Little Glassywing is not a common butterfly in Wisconsin. When 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, and now seldom see more than a few each year. 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 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 to this species, and these three species are often referred to as the “three witches” in the literature. All three skippers are very dark, and if they are all moving around together it is indeed somewhat difficult to differentiate each species.

The Dun Skipper is much darker above and its light spots are 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, orangish coloration on the leading edge of the forewing 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.

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 the most I have ever seen in one day was seven.

Recent Little Glassywing Sightings

Date County Reported by
Jul 19, 2014 Dunn Pam Campbell
Jul 19, 2014 Ozaukee Jym Mooney
Jul 16, 2014 Fond du Lac Northern Kettle Morain...
Jul 14, 2014 Ozaukee Jym Mooney
Jul 13, 2014 Grant Dubuque NABA Butterfly...

Locations

Map showing sighting locations for Little Glassywing
Map key
Little GlassywingClick to enlarge

Female

Northern Kettle Moraine Forest, Fond du Lac Co., WI, July 14, 2003.

Little GlassywingClick to enlarge

Female

Northern Kettle Moraine Forest, Fond du Lac Co., WI, July 14, 2003.

Little GlassywingClick to enlarge

Male

Page Creek Marsh, Marquette Co., WI, July 11, 2004.

Little GlassywingClick to enlarge

Male

Page Creek Marsh, Marquette Co., WI, July 11, 2004.

Little GlassywingClick to enlarge

Waumandee Creek Farm, Buffalo Co., WI, July 15, 2005.

Little GlassywingClick to enlarge

Prairie Haven Farm, Buffalo Co., WI. July 10, 2007.