Great Basin Wood Nymph (Cercyonis sthenele [Boisduval])
Wing span: 1 3/8 - 1 3/4 inches (3.5 - 4.5 cm).
Identification: Upperside is brown. Forewing of male has 2 small eyespots, with the upper one larger; female has 2 large eyespots of about the same size. Eyespots are of equal distance from the outer edge of wing. Dark basal half of hindwing underside is separated from lighter outer half by an irregular dark line.
Life history: Males patrol all day to find females, who lay eggs singly on host plants. Caterpillars hatch and go into hibernation, not feeding until the following spring.
Flight: One brood from June-August.
Caterpillar hosts: Unknown grasses.
Adult food: Flower nectar.
Habitat: Chaparral, oak woodland, open pine forest, juniper-pinyon woodland, sagebrush.
Range: Southern British Columbia south through California to Baja California Norte; east to Wyoming, Colorado, and Arizona.
Conservation: Not usually required.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management needs: None reported.
Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. Tilden, J. W. 1986. A field guide to western butterflies. Houghton-Mifflin Co., Boston, Mass. 370 pages, 23 color plates.
Author: Jane M. Struttmann
State and Regional References:
Elrod, M.J. 1906. The Butterflies of Montana. Bulletin of the University of Montana 30: 1-174. Ferris, C.D. and F.M. Brown. 1980. Butterflies of the Rocky Mountain States. University of Oklahoma Press. Norman. Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass.