wild indigo duskywing

not listed

N5 - Secure

SU - Unrankable

not listed

Wild indigo duskywing is a medium-sized spread-wing skipper. It is ¾″ in length and has a wingspan of 1⅜″ to 1⅝″.

The wings are dark brown. The upperside of the forewing is very dark on the basal half, appearing “oily”. At the end of the cell there is a distinct, light, orangish-brown or reddish-brown patch. There are several spots, including a cluster of four white translucent spots at the leading edge in the region just before the tip (subapical area); two white subapical spots near the middle; and a row of pale marginal spots. The hindwing has a faint cell end bar, a row of white marginal spots, and a row of pale submarginal spots.

The antennae are short and striped. Each antenna has a black swelling (club) at the tip, and a pale, thin, hooked extension (apiculus) at the end of the club.

Total length: ¾″

Wingspan: 1⅜″ to 1⅝″

Columbine duskywing (Erynnis lucilius) is nearly identical but is much rarer. It is slightly smaller, slightly lighter, and the forewings are shorter. It may not be possible to distinguish between the two adults in the field unless the specimen is on or near a caterpillar host plant.

Fields and other grassy areas with crown vetch, roadside embankments, railroad rights-of-way

Two generations per year: Late May through June and mid-July to late August

Caterpillars feed at night. During the day they remain in a webbed shelter inside a rolled leaf.

Adults hold their wings flat when at rest.

Males perch on low shrubs in open areas waiting for passing females. The female lays eggs singly on the foliage of host plants. Larvae make a webbed shelter by rolling a leaf and tying it with silk. They live in their shelters, exiting only at night to feed. Second generation larvae overwinter in their shelters as late instar caterpillars and pupate in their shelters in the spring.

Wild indigo, lupine, and crown vetch

This skipper was originally a species of open woodlands and shrubby prairies. The larvae fed on mostly on horseflyweed (Baptisia tinctoria) but also on blue wild indigo (Baptisia australis) and on sundial lupine (Lupinus perennis). With the decline of those plant species due to habitat loss, the skipper adapted to the introduced, locally abundant species crown vetch (Securigera varia).

Nectar from flowers, including crown vetch; blackberry; blueberry; common strawberry; wild bergamot; red, white, alsike, and crimson clovers; white and yellow sweet clovers; bird’s-foot trefoil; garlic mustard; blazing stars; black-eyed Susan; prairie ironweed; chicory; Canadian horseweed; common dandelion; Joe Pye weeds; thistles; sunflowers; asters; and dogbane.

Sources

21, 24, 27, 29, 30, 71, 82.

Widespread, abundant, and increasing in the east and the Midwest, rare in Minnesota

NatureServe lists this species as “Unrankable” for the state of Minnesota. Its range is rapidly expanding and its numbers are increasing wherever crown vetch has been widely planted.

Skippers have traditionally been placed in their own superfamily Hesperioidea because of their morphological similarity. Recent phylogenetic analysis (Kawahara and Breinholt, 2014) suggests that they share the same common ancestor as other butterfly families, and thus belong in the superfamily, Papilionoidea.

Location: La Crescent, MN, backyard

Location: Afton State Park

There is no wild indigo at Afton SP, but it is said that this species has adapted to crown vetch as a host plant, and there is quite a bit of that at Afton SP.