The Dreamy Duskywing is a member of the family Hesperiidae, the large worldwide family of butterflies known as skippers. All skippers have recurved antennal tips, or ‘clubs’. The skippers, for the most part, fit into two subfamilies, the Pyrgine or spreadwing skippers, and the Hesperine or grass skippers, sometimes also called monocot skippers. As the common name suggests, spreadwing skippers rest with their wings flat and outspread. By contrast most grass skippers rest with their wings in two planes, the hind wings out flat and the forewings partially elevated at an angle. In Washington there are 30 species of skippers, 12 of which are spreadwing skippers. Within the genus Erynnis we have five species in Washington, one of which is poorly documented at present. Skippers in the genus Erynnis are notoriously difficult to identify. One Washington species, the Afranius Skipper, is so difficult to separate from the common Persius Skipper that its reported occurrence in Washington’s Blue Mountains is still under debate. Our species, the Dreamy Duskywing, is the most easily identified member of this genus. Erynnis icelus is a small skipper, a common species in Washington, rarely found in large numbers. It normally occurs singly or in small numbers along unpaved roadbeds and in cleared scrub areas, sometimes at mud, and often perching on dead woody material. Erynnis icelus flies early in the season, with records as early as mid April, and has been recorded into late July at higher elevations.

surface of the front wing, just beyond the mid point of the leading edge. There are no hyaline (clear) spots on the forewing, as occur in most other members of this genus. Females tend to be larger than males, and males can additionally be identified by a recurved structure (androconial fold) along the leading edge of the forewing. This structure contains pheremone producing scales.

surface of the front wing, just beyond the mid point of the leading edge. There are no hyaline (clear) spots on the forewing, as occur in most other members of this genus. Females tend to be larger than males, and males can additionally be identified by a recurved structure (androconial fold) along the leading edge of the forewing. This structure contains pheremone producing scales.

The Dreamy Duskywing occurs throughout much of southern Canada and northern America, extending south as far as Georgia in the east, and New Mexico and California in the west, but is absent from the southern great plains and the gulf states. In Washington State E. icelus is found throughout the mountainous and foothill areas of the east, and in the west is found from the Cascades to the Puget Trough. This species is generally absent from the Pacific Ocean counties and from all but the southeast foothills of the Olympic Mountains. The Dreamy Duskywing is single-brooded, overwintering as an adult larva. In the spring the larva pupates without further feeding, then emerges as an adult. After mating the female oviposits her eggs singly on the underside of host plant leaves, usually willow but sometimes also aspen, birch, poplar or locust. Early larval stages eat small holes clear through the leaves. The larva also cuts the leaf in two places, from the margin halfway to the mid-vein, then folds the intervening leaf segment over and anchors it in place with silk to form a nest in which it spends most of its resting time. Later, the larger instars silk whole leaves together in a stack to make their nests. The larvae, which have the typical skipper “collar” constriction behind the head, eat prodigiously but grow slowly. captivity from the egg In cycle to diapausing 5th instar was seven weeks. Eventually the larvae eat less and then become sluggish, eventually entering diapause (late July in a reared brood from an early June female in Yakima County). Throughout all stages the larvae tend to rest with their heads crooked back parallel to the body like a walking cane, a posture which is common in skipper larvae. After overwintering the mature larva is quite slow to pupate, shrinking and taking several weeks then finally forming a surprisingly small chrysalis in comparison to the rather large larva. Large larvae and small chrysalids seem to be a common theme among skippers. The adult Dreamy Duskywing is identified by an obvious large hoary (whitish) patch on the dorsal surface of the front wing, just beyond the mid point of the leading edge. There are no hyaline (clear) spots on the forewing, as occur in most other members of this genus. Females tend to be larger than males, and males can additionally be identified by a recurved structure (androconial fold) along the leading edge of the forewing. This structure contains pheremone producing scales.

All Photos by Dave Nunnallee

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