Avalon Scrub-Hairstreak (Strymon avalona [Wright])
Wing span: 3/4 - 1 inch (1.9 - 2.5 cm).
Identification: One short tail on the hindwing. Upperside gray; hindwing with red or yellow spot near tail; may have small white spots at margin. Underside ashy gray, slightly darker on inner half of wing. Submarginal and postmedian lines faint or lacking.
Life history: Eggs are laid on terminal buds and on flower buds.
Flight: Many broods from February-December.
Caterpillar hosts: Silverleaf lotus (Lotus argophyllus var. ornithopus) and deerbrush (Lotus scoparius).
Adult food: Nectar from flowers including common sumac (Rhus laurina) and giant buckwheat (Eriogonum giganteum).
Habitat: Chaparral and grassy areas.
Range: Found only on Santa Catalina Island, off the coast of southern California.
Conservation: This species is one of the most limited U. S. species and should be conserved.
The Nature Conservancy Global Rank: G3 - Very rare or local throughout its range or found locally in a restricted range (21 to 100 occurrences). (Threatened throughout its range).
Management needs: Maintain stands of host plants. Prevent loss or destruction of habitat.
Emmel, T. C. and J. F. Emmel. 1973. The butterflies of southern California. Science Series 26. Natural History Museum of Los Angeles County, Los Angeles, California. 148 pages, 10 color plates. 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.