Columbine Duskywing (Erynnis lucilius)
By Melissa Simpson, Ecologist Chequamegon-Nicolet National Forest, Eastern Region
The Columbine Duskywing (Erynnis lucilius) belongs to the skipper family, Hesperiidae. This family is known as the Skippers because the butterflies exhibit a rapid, erratic "skipping" flight pattern. The Skippers are not considered to be "true" butterflies, but are more closely related to the true butterflies than are the moths. The Columbine Duskywing is in the Subfamily Pyrginae, commonly known as the spread-wing skippers because they hold both sets of their wings open when landed.
The dorsal side of the forewing is mottled with black, brown and faint tan patches with several small white spots towards the apex. There is a brown patch at end of forewing cell that is indistinct. The ventral side of the hindwing has a marginal row of white spots. The dorsal side of the hindwing is dark with blurry pale spots in one or two rows toward the wing margin and a thin black marginal line with a gray fringe. Caterpillars are pale green with a dark green dorsal line and a black head.
This species is found in rocky deciduous and mixed forests and woodland edges, as well as glades and barrens where there is an abundance of its larval host plant, wild columbine (Aquilegia canadensis). They are bivoltine and females lay their eggs singly on the underside of the columbine leaves (see photo) from April to June and July to September throughout its range. The second brood overwinters as fully-developed caterpillars in leaf litter at the base of the host plant.
The Columbine Duskywing is assigned a NatureServe global rank of “G4 - Apparently secure globally,” though it might be quite rare in parts of its range, especially at the periphery. High deer densities (greater than 20 per square mile) may negatively impact this species as deer browse on columbine. Pesticide spraying for gypsy moth control may also reduce the populations in localized areas.