Muir's Hairstreak (Callophrys muiri [Hy. Edwards])
Wing span: 7/8 - 1 inch (2.2 - 2.5 cm).
Identification: Upperside of male is dark brown with dark orange patches on lower outer edges of wings; female is tawny with dark margins. Underside is dark purple-brown with an iridescent green sheen. Postmedian line is very irregular; dark toward the base of wing, white toward the outer margin. Blue-gray patch near hindwing margin contains 3-4 reddish spots; 3-4 small black spots are near this patch.
Life history: To seek females, males perch on host trees all day. Eggs are laid singly on tips of host plant leaves, which the caterpillars eat. Chrysalids hibernate.
Flight: One brood from April-May.
Caterpillar hosts: Cypress, especially Sargent cypress (Cupressus sargentii) and MacNab's cypress (Cupressus macnabiana).
Adult food: Nectar from flowers of wild lilac (Ceanothus) and other plants.
Habitat: Hilly, rocky areas.
Range: California's Coast Ranges from San Luis Obispo County north to Mendocino County; Guadeloupe Island, Mexico.
Conservation: This butterfly is of moderate concern.
The Nature Conservancy Rank: T3 - Very rare or local throughout its range or found locally in a restricted range (21 to 100 occurrences). (Threatened throughout its range).
Management needs: Conserve as many habitats as possible. Inventory and monitor populations.
Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. 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, J.W., Real, H.G., and D.K. Faulkner. 1992. Butterflies of Baja California. Lepidoptera Research Foundation, Beverly Hills, Calif. Comstock, J.A. 1927. Butterflies of California. Privately published, Los Angeles, Calif. [Facsimile available from Entomological Reprint Specialists, Los Angeles, Calif.] Dameron, W. 1997. Searching for butterflies in southern California. Flutterby Press, Los Angeles, Calif. Emmel, T.C. Editor. 1998. Systematics of western North American butterflies. Mariposa Press, Gainesville, Florida. Emmel, T. C. and J. F. Emmel. 1973. The Butterflies of Southern California. Natural History Museum of Los Angeles County Science Series No. 26. Garth, J.S. and J.W. Tilden. 1986. California Butterflies. California Natural History Guide 51. University of California Press, Berkeley and Los Angeles. Langston, R.L. 1981. The Rhopalocera of Santa Cruz Island, California. Journal of Research on the Lepidoptera 18: 24-35. Miller, Scott E. 1985. Butterflies of the Califorenia Channel Islands. Journal of the Research on the Lepidoptera 23: 282-296. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Orsak, L.J. 1977. The Butterflies of Orange County, California. Museum of Systematic Biology, University of california, Irvine. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Steiner, J. 1990. Bay Area Butterflies: The Distribution and Natural History of San Francisco Region Rhopalocera. Hayward, Calif.: Hayward State University, Masters Thesis. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass. Tilden, J.W. 1965. Butterflies of the San Francisco Bay Region. California Natural History Guide 12. University of California Press, Berkeley and Los Angeles.