Polites themistocles
Tawny-Edged Skipper

Family:Hesperiidae
Family Description:
Description:
Caterpillar: The caterpillar varies in color and can be yellowish, greenish, maroon, or brown. It is dotted and faintly striped lengthwise with black. The head is black and marked with white.
Adult: This is a small skipper (wingspan to 1 inch), with wings that look like little triangles. The upperside is brown to dark brown, shaded with orange on the leading edge of the forewing. The male has a black stigma (patch of scent scales used in attracting females) near the center of the forewing; the female instead has several yellowish spots. The hindwing is unmarked. Underneath is brownish orange, sometimes darker where the wings attach to the body, and without any distinct markings. The underside of the hindwing may have several faint spots in a curved row.

Range:
This widespread species ranges from southern British Columbia east across southern Canada to Nova Scotia. In the U.S., it ranges from northern Washington, western Montana, central Colorado, and eastern Texas east to the Atlantic; it also occurs in Utah, Arizona, and New Mexico, as well as in isolated portions of Oregon and California. It is rare in Idaho, and has been documented to occur only in three counties along the eastern border: Fremont, Caribou, and Bear Lake.

Habitat:
The preferred habitat varies across its near high elevation lakes in the northwest, forests in California, and prairies and grassy places in the east.

Diet:
Caterpillar:
Caterpillars feed on the leaves of several varieties of grasses, including panic grass (Panicum spp.), slender crabgrass (Digitaria filiformis), and bluegrass (Poa spp.).

Adult: Butterflies drink flower nectar.

Ecology:
The number of generations of caterpillars each year varies throughout the range of this species, with only one in the north and west, two to several in the Plains states to the east coast, and many throughout the year in Florida. Caterpillars construct nests with leaves tied with silk. Pupae from the last generation of the growing season may overwinter in a physiological state called diapause. Adults generally fly in July (northern part of its range and at higher elevations) or from April through September (southern part of its range and at lower elevations). The butterflies when at rest are found with their forewings partially open and their hindwings fully open.

Reproduction:
Males perch to wait for receptive females. Females lay eggs singly on or in the vicinity of 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.