Cercyonis sthenele
Great Basin Wood-Nymph

Family:Satyridae
Family Description:
Alternate Common Names:
Sthenele Wood-Nymph, Scrub Wood-Nymph, Boisduval’s Wood-Nymph.
Description:
Caterpillar:
The caterpillar is light green and marked lengthwise with dark green stripes along the back and yellowish stripes along the sides.
Adult: The butterfly is medium-sized, with a wingspan of 1 3/8 to 2 inches. The upperside is brown, with two eyespots that may be edged in yellow on the forewing. The hindwing may or may not have smaller eyespots. Underneath is brown to gray and lightly striped; the hindwing is divided into a darker, inner half and a lighter, outer half by a wavy dark line. Eyespots similar to the upperside are present.

Range:
This species is found only in the west, ranging from southern British Columbia south through California, and east to western Montana, Wyoming, Colorado, and northwestern New Mexico. In Idaho, it occurs primarily in the central and southern portions of the state.

Habitat:

It is found in drier habitats, such as sagebrush steppe, chaparral, and woodlands of oak, pine, or juniper.

Diet:

Caterpillar: Caterpillars feed on the leaves of various grasses (Poaceae).
Adult: Butterflies are known to drink flower nectar from California buckeye (Aesculus californica), white sweet clover (Melilotus alba), and other flowers.

Ecology:

There is one generation of caterpillars each year. The caterpillars hatch close to the end of the growing season and overwinter in a physiological state called diapause, without ever feeding. In spring they emerge to feed, molt, and eventually pupate. Adults generally fly from May through September. Butterflies often rest on tree trunks.

Reproduction:

Males actively patrol to find receptive females. Females lay off-white, round eggs singly on host plants.

Conservation:
Idaho Status: Unprotected nongame species.
Global Rank: G5
populations are widespread, abundant, and secure.


References:
Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.  Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.