Piruna pirus
Russet Skipperling

Family Description:
Alternate Common Name: Pirus Skipperling.

The caterpillar is green, covered with whitish hair, and marked lengthwise with several white and green lines.  The head is brownish green and marked with orangish brown and offwhite stripes. 
Adult: This is a fairly small skipper, with a wingspan of 1 to 1 1/8 inches. The upperside is brown, velvety in appearance, and unmarked except for a scattering of tiny white dots, three of which are in a row at the tip of the forewing. Underneath, the forewing is mostly dark brown with the outer edge reddish brown, or it may be entirely reddish brown; the dots from above show through. The underside of the hindwing is reddish brown and unmarked.

This species exhibits a small range in the intermountain west and southwestern U.S., extending from southeastern Idaho and southern Wyoming, through Utah and Colorado, to parts of Arizona and New Mexico.

It occurs in moist valleys and gulches, open oak woodlands, and in riparian areas.

Though records are sparse, caterpillars are believed to feed on the leaves of grasses (Poa spp.).

Adult: Butterflies drink flower nectar, often from dogbane (Apocynum spp.) and alfalfa (Medicago spp.).

There is one generation of caterpillars each summer. Caterpillars construct nests from leaves tied with silk. Mature caterpillars overwinter in a physiological state called diapause. Adults generally fly from the end of May through the first of August. Butterflies bask in the sun with their forewings partially open and their hindwings fully open.

Males actively patrol in search of receptive females. The site chosen by females for oviposition has not been reported.

Idaho Status: Unprotected nongame species.
Global Rank: G5
populations levels are secure, but may be of concern in the future.

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.