Variable Checkerspot (Euphydryas chalcedona [Doubleday])
Wing span: 1 1/4 - 2 1/4 inches (3.2 - 5.7 cm).
Identification: Extremely variable. Forewing narrow. Upperside is black to dark orange-brown with yellow, red, and sometimes white spots. Underside with yellow and orange-red bands.
Life history: Males perch or patrol all day for females. Eggs are laid in large groups on underside of leaves of host plants. Caterpillars feed together on leaves, flowers, or bracts in a silk nest. Third- and fourth-stage caterpillars hibernate under rocks or in litter. Caterpillars in high elevations can hibernate for several years.
Flight: One flight; April-June in California and Oregon, June-July in the north and higher elevations. Several flights from April-October in western Arizona, southern Nevada, and the Mojave Desert.
Caterpillar hosts: Besseya, penstemon, and Indian paintbrush (Scrophulariaceae); snowberry and honeysuckle (Caprifoliaceae); and plants from several other families including Boraginaceae and Rosaceae.
Adult food: Flower nectar.
Habitat: Sagebrush flats, chaparral, desert hills, high prairie, open forest, alpine tundra.
Range: Alaska south along the Pacific Coast through California and Arizona to Baja California and Mexico; east to Montana, the Dakotas, Wyoming, Colorado, New Mexico.
Conservation: Some subspecies and unnamed populations may require monitoring, management, or preservation.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management needs: Maintain habitat integrity, host plant colonies, and nectar sources.
Note: This species is treated by some as three separate species Euphydryas anicia, E. chalcedona, and E. colon.
Opler, P. A. and V. Malikul. 1992. A field guide to eastern butterflies. Peterson field guide #4. Houghton-Mifflin Co., Boston. 396 pages, 48 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, F.M., Eff, J.D., and B. Rotger. 1957. Colorado Butterflies. Denver Museum of Natural History, Denver. Ferris, C.D. and F.M. Brown. 1980. Butterflies of the Rocky Mountain States. University of Oklahoma Press. Norman. Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass.