little glassywing

not listed

N5 - Secure

SU - Unrankable

not listed

Little glassywing is a medium-sized grass skipper with a wingspan of 11 ⁄16″ to 1½″.

The upperside of the both wings is dark brownish-black. The forewing has a cluster of four spots near the center and a row of three smaller spots near the margin. The central cluster consists of one large semi-transparent spot with two smaller pale spots above it and one smaller pale spot below it. The large spot is rectangular on the male, square on the female. The semi-transparent spot is what gives this species its common name. The underside of both wings is dark brown. The underside of the hindwing has a central band of very pale spots.

The antennae are short and barred. Each antenna has a black swelling (club) at the tip; a white band just below the club; and a pale, thin, hooked extension (apiculus) at the end of the club.

The caterpillar is green with a black head. The thorax and abdomen are moderately covered with short brown hairs, each with a brown bulbous base. Mature caterpillars are seen in early spring.

Wingspan: 11 ⁄16″ to 1½″

Northern broken-dash, Dun skipper, and little glassywing are called “the three witches” because their dark wings make it difficult to tell “which one is which.”

Dun skipper (Euphyes vestris) male has no pale spots on the forewing and no row of faint spots on the hindwing below. The female has only two pale spots on the forewing.

Northern broken-dash (Wallengrenia egeremet) has an orangish area on the leading edge of the forewing. The rectangular spot is smaller, orange or yellow, and not as square.

Moist woodland openings and edges, moist brushy fields near woodlands, wetland edges, roadsides. Always near trees.

One brood: mid June to early August

Little glassywings often fly together with Dun skipper and northern broken-dash.

Like all skippers, they have a rapid, darting flight.

Males perch on low vegetation after noon waiting for passing females. The female lays pale greenish to white eggs in the afternoon on the leaves of purpletop tridens. Caterpillars make a shelter by rolling one leaf or tying adjacent leaves together with silk. They live in their shelters, exiting only at night to feed. They overwinter in their shelters as partially grown larvae and pupate in their shelters in the spring.

Leaves of purpletop tridens (Tridens flavus var. flavus)

Flower nectar of white, pink, and purple flowers, especially dogbane and milkweed. When those are not available, also nectar from yellow flowers.

Sources

6, 7, 20, 21, 24, 29, 71.

Uncommon in Minnesota

Location: St. Francis, Anoka County

Location: Schaar's Bluff, Dakota County

This photo was taken today, along the bike trail about 1 mile east of the Schaar's Bluff trailhead in Dakota County Parks.

It is a "little glassywing" skipper.  We only saw one.

Careful study of Butterflies through Binoculars East by Jeffrey Glassberg (NABA president) and also the material on the Wisconsin Butterflies site agree on this identification.  The Wisconsin site says it is fairly uncommon in WI.  Their map shows at least a few sightings in WI counties just east of the Twin Cities.  Their data shows that early July is when this species is seen.