Hesperia juba
Juba Skipper

Family Description:
Alternate Common Name: Jagged-Border Skipper.

Caterpillar: When young, the caterpillar is offwhite to yellow with a brownish head. It becomes a dull green with a dark head when older.
Adult: This is a medium to large-sized skipper, with a wingspan of 1 1/4 to 1 5/8 inches. The forewings appear pointed. Males are orange on the upperside and marked with brown, particularly along the outer edges of the wings, and on the interior of the hindwing. Males have a stigma (patch of scent scales used in attracting females) that forms a blackish streak on the forewing. Females are larger and brighter orange, and are marked with brown. Underneath, both sexes are brownish orange on the forewing and greenish orange on the hindwing. The underside of the hindwing is marked with an uneven white band or row of spots.

This species ranges from central British Columbia south to southern California, and east to Montana south to northern New Mexico. In Idaho, it is found throughout most of the state.

It occurs in open areas such as sagebrush steppe, chaparral, grasslands, and open woodlands.

Caterpillars feed on the leaves of several grasses, including slender hairgrass (Deschampsia elongata), needlegrass (Stipa spp.), and bluegrass (Poa spp.).

Adult: Butterflies drink flower nectar.

Caterpillars live in nests made from leaves tied with silk. There are two generations of caterpillars each summer, the second of which some experts report overwinters in a physiological state called diapause. However, other experts point to the fact that adults can be observed in flight as early as April, suggesting the pupae overwinter as well. Adults generally fly from late April through June and from August to early October.

Males perch to wait for receptive females. Females lay pinkish eggs singly on or near host plants. The eggs turn white or gray before hatching.

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. 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.