Callophrys affinis
Western Green Hairstreak

Family Description:
Alternate Common Names:Bramble Green Hairstreak, Green Hairstreak, Immaculate Green Hairstreak, Affinis Green Hairstreak.
Note: The green hairstreaks of the genus Callophrys can be difficult to identify. There is still some debate among scientists about the exact boundaries between some species.

Caterpillar: The caterpillars vary considerably in color. They may be yellowish green, bluish green, bright green, pink or red in color, and they may be with or without white or yellow stripes. Generally, they appear "bumpy" like a washboard due to their segmentation.
Adult: The butterfly is fairly small, with a wingspan of 7/8 to 1 1/8 inches, and its appearance is variable. The upperside ranges in color from gray to orange to brown and is unmarked. The underside is yellowish green; the forewing may have an uneven orange or gray patch, while the hindwing is generally solid green and marked with a line of faint white spots spaced well apart. Although many hairstreaks have a thin tail extending off the hindwing, this species does not.

This is a western species, ranging from southern British Columbia and Alberta south through the Pacific Northwest and California, and east to central Montana and south to New Mexico. It has been found scattered throughout the state of Idaho.

Generally this species is found on open sunny slopes with low vegetation. This includes sand dunes, chaparral, brush, and forest openings.

Caterpillars eat the flowers, fruits, and occasionally leaves of several species of plants, including buckwheat (Eriogonum spp.), trefoils (Lotus spp.), and buck brush (Ceanothus spp.).

Adult: Butterflies drink flower nectar.

There is one generation of caterpillars each summer. The caterpillars pupate, then overwinter within their chrysalises in a physiological state called diapause until spring. Adults generally fly from May through June.

Males perch and wait for receptive females to pass by. Females lay eggs singly on the flower buds of host plants.

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.