Juba Skipper (Hesperia juba [Scudder])
Wing span: 1 1/4 - 1 5/8 inches (3.2 - 4.2 cm).
Identification: Male is bright orange-brown with a dark border that is toothed inwardly. Female is larger than male, with more and brighter markings. Underside of hindwing is a slightly greenish brown, with large jagged white spots. Basal spot on submarginal row is displaced inwardly.
Life history: To await females, males perch in gulches all day. Females deposit eggs singly on or near the host plant. Caterpillars eat leaves and make nests of silked-together leaves. Probably caterpillars hibernate.
Flight: Two broods from May-June and August-September.
Caterpillar hosts: Slender hairgrass (Deschampsia elongata), needlegrass (Stipa), foxtail brome (Bromus rubens), and bluegrass (Poa pratensis).
Adult food: Nectar from flowers including rabbitbrush.
Habitat: Sagebrush, chaparral, hilly grasslands, open woodland.
Range: British Columbia south to southern California; east to Montana, Wyoming, Colorado, and northwest New Mexico.
Conservation: Not usually required.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management needs: None reported.
Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. Stanford, R. E. and P. A. Opler. 1993. Atlas of western USA butterflies including adjacent parts of Canada and Mexico. Denver and Fort Collins, CO. Tilden, J. W. 1986. A field guide to western butterflies. Houghton-Mifflin Co., Boston, Mass. 370 pages, 23 color plates.
Author: Jane M. Struttmann
State and Regional References:
Brown, F.M., Eff, J.D., and B. Rotger. 1957. Colorado Butterflies. Denver Museum of Natural History, Denver. Ferris, C.D. and F.M. Brown. 1980. Butterflies of the Rocky Mountain States. University of Oklahoma Press. Norman. Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass.