Erebia epipsodea
Common Alpine

Family Description:
Alternate Common Name: Butler’s Alpine.
Caterpillar: The caterpillar is yellowish green, marked lengthwise with a dark green stripe along the back and yellow and brown stripes along the sides. The head is yellowish brown, and there are two short, erect extensions at the rear.
Adult: The butterfly is medium-sized, with a wingspan of 1 to 2 inches. It is dark brown on the upperside. The forewing has an orange patch at the tip; inside the patch are two black eyespots with white centers. The hindwing has a row of small black spots outlined in orange along the outer edge. Underneath, the wings are brown to gray and similarly marked.

This species occurs from central Alaska south to northern Oregon, along the Rockies to northern New Mexico, and east to western Manitoba and central Montana. It occurs through much of Idaho.

This species utilizes a wide variety of open habitats, including open woodlands, meadows, bogs, fields, and sagebrush steppe.


Caterpillar: Caterpillars feed on grasses (Poaceae); the specific host plant species have not been observed or reported.
Adult: Butterflies drink flower nectar.

There is one generation of caterpillars each summer. Caterpillars overwinter in a physiological state called diapause, and emerge in spring to continue feeding and molting, and eventually to pupate. Adults generally fly from June to July, but may be seen as early as May and as late as October. 

Males actively patrol to search for receptive females. Females lay white eggs, either singly or in small clusters, on grasses (Poaceae) or dead leaves.

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

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. (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.