Great Basin Wood-Nymph (Cercyonis sthenele) (Boisduval, 1852)
Diagnosis: A dark brown butterfly with rounded wings, sthenele has two prominent eye-spots with white pupils on the forewing above and below. The upper (anterior) spot is usually larger (never smaller) than the lower one, and both are equidistant from the wing margin. There are usually no hindwing eye-spots above or beneath. Wingspan: 39 to 44 mm.
Subspecies: Four have been named, but only subspecies paulus is found in Canada.
Range: Cercyonis sthenele is found over much of the western U.S., but reaches Canada only in British Columbia, where it occurs as far north as the Fraser River at Highway 20.
Similar Species: The Common Wood-Nymph (C. pegala). The Small Wood-Nymph (C.oetus) usually lacks the lower eye-spot in males, and it is closer to the wing margin than the upper eye-spot in females. [compare images]
Early Stages: The larvae are similar to those of Common Wood-Nymph (C. pegala). They feed on various species of grasses and hibernate in the first instar.
Abundance: The Great Basin Wood-Nymph is locally common in southern British Columbia.
Flight Season: It flies from late June to late August.
Habits: Cercyonis sthenele flies in dry open woodlands and sagebrush areas, and is often seen nectaring on flowers.
© 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.
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