California Hairstreak (Satyrium californica [W. H. Edwards])
Wing span: 1 - 1 1/4 inches (2.5 - 3.2 cm).
Identification: Each hindwing has 1 long and 1 short tail. Upperside brown with orange spot on hindwing near tails. Outer edge of forewing usually has row of orange spots. Underside brown-gray with orange submarginal crescents and a postmedian band of black spots.
Life history: Males search for females by perching on top of trees (occasionally patrolling). Females lay eggs, glued together in groups of 2-4, in bark crevices. Eggs hibernate until the following spring. Caterpillars eat leaves.
Flight: One flight from May-August.
Caterpillar hosts: Amelanchier alnifolia, Prunus virginiana; Cercocarpus, Ceanothus, Quercus, and Salix species.
Adult food: Nectar from flowers of wild buckwheat, milkweed, sulphur flower, and others.
Habitat: Chaparral, brushland, forest edges, open woodland.
Range: British Columbia south to southern California and east to Colorado.
Conservation: Valley oak-associated population in California's central valley is threatened by loss of habitat.
The Nature Conservancy Global Rank: G4 - Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery.
Management needs: Conserve remaining stands of Valley oak in California Central Valley.
Brown, J. W., H. G. Real, and D. K. Faulkner. Butterflies of Baja California. 1992. Lepidoptera Research Foundation, Inc., Beverly Hills, CA. 129 pages, 8 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