Sleepy Duskywing
Erynnis brizo (Boisduval & Le Conte, [1837])

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Diagnosis: Erynnis brizo is a larger duskywing (wingspan: 28 to 35 mm), lacking any light forewing markings. There are two distinct dark-edged purple-grey bands across the forewings, the outer one usually with a zigzag margin or almost broken into segments.

Subspecies: Four subspecies have been named, but only the nominate subspecies brizo occurs in Canada.

Range: The species occurs throughout the eastern and southwestern U.S., reaching Canada only in southern Ontario, northeast to near Hamilton, and in southern Manitoba and southeastern Saskatchewan. The maps in Opler and Malikul (1992) showing Quebec records and in Holmes et al. (1991) showing records throughout southern and eastern Ontario are in error, owing to confusion with icelus. At present, brizo is known to occur in only three areas of southern Ontario: Lambton County (Pinery Provincial Park area), Norfolk County (St. Williams area), and the south shore of Lake Ontario (Hamilton to Grimsby).

Similar Species: The Dreamy Duskywing (E. icelus) [compare images].

Early Stages: The pale green larvae have a dark dorsal stripe and paler lateral stripes, and live in leaf-nests on the foodplants, always species of oaks (Fagaceae). In Manitoba, only Bur Oak (Quercus macrocarpa) is used.

Sleepy Duskywing (Erynnis brizo brizo), larva. W. Lukey

Abundance: Uncommon over all of its Canadian range, it is found only in exactly the right habitat.

Flight Season: There is one generation, which flies from very early May to mid-June.

Habits: This species is regularly seen at flowers in oak woods, on the ground in the typical duskywing posture, and at mud puddles, where they can sometimes be seen in association with icelus where their habitats converge.

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.

The Toronto Entomologists' Association thanks Agriculture and Agri-Food Canada for providing the content and computer code for this web page.