Moss' Elfin (Callophrys mossii [Hy. Edwards])
Wing span: 7/8 - 1 1/8 inches (2.2 - 2.8 cm).
Identification: Upperside of male grayish brown with a tan patch on hindwing inner margin; female light brown to tan with dark borders. Underside coppery brown to purplish brown; inner half of hindwing darker than light outer half.
Life history: In California, males perch on shrubs or at tops of cliffs to watch for females; in Colorado they perch in gulches. Eggs are laid singly on the underside of host plant leaves. Young caterpillars feed on leaves; older ones on flowers and fruits. Chrysalids hibernate.
Flight: One flight from March-June.
Caterpillar hosts: Stonecrop (Sedum, Sedella, Dudleya, and Parvisedum) species in the Crassulaceae family.
Adult food: Not reported.
Habitat: Rocky outcrops, woody canyons, cliffs.
Range: Patchy, isolated populations from British Columbia south to southern California, east to Wyoming and Colorado.
Conservation: The San Bruno Elfin (Callophrys mossii bayensis) is listed as Endangered by the U. S. Fish & Wildlife Service. This subspecies is limited to the San Bruno Mountains in San Mateo County, California and a few nearby sites.
The San Bruno Elfin has The Nature Conservancy Rank of T1 - Critically imperiled because of extreme rarity (5 or fewer occurrences, or very few remaining individuals), or because of some factor of its biology making it especially vulnerable to extinction. (Critically endangered throughout its range).
Management needs: Protect habitat of the San Bruno Elfin and other limited populations from development and encroachment by non-native plants.
Matthews, J. R., editor. 1990. The official World Wildlife Fund guide to endangered species of North America, Vol. 2. Beacham Publishing, Inc., Washington, D. C. 636 pages. 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.