Great Basin Fritillary (Speyeria egleis [Behr])
Wing span: 1 3/4 - 2 3/8 inches (4.5 - 6 cm).
Identification: Upperside bright to dull orange-brown with dark markings evenly spaced. Underside of hindwing has triangular, silver submarginal spots; other spots small with brown edging; spots may or may not be silvered.
Life history: Males patrol during the day for females, who lay eggs on leaf litter near violets. First-stage caterpillars hibernate unfed until spring, when they feed on violet leaves.
Flight: One brood from late June-August.
Caterpillar hosts: Violets including Viola adunca, V. nuttallii, V. purpurea, and V. walteri.
Adult food: Flower nectar.
Habitat: Mountain meadows, forest openings, exposed rocky ridges.
Range: North Dakota southwest through Oregon to California, south to Colorado.
Conservation: Not usually of concern but subspecies tehachapina has a very small range and could be devastated by a single event.
Speyeria egleis tehachapina has The Nature Conservancy rank of T3 -Very rare or local throughout its range or found locally in a restricted range (21 to 100 occurrences). (Threatened throughout its range).
Speyeria egleis as a whole has the The Nature Conservancy Global Rank of G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management needs: Monitor subspecies tehachapina and evaluate for conservation action.
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.