Orange Sulphur (Colias eurytheme Boisduval)
Wing span: 1 3/8 - 2 3/4 inches (3.5 - 7 cm).
Identification: Quite variable. Upperside of male yellow with orange overlay, yellow veins, wide black border, and dark black cell spot. Female yellow or white with irregular black border surrounding light spots. Underside hindwing spot silver with 2 concentric dark rings, and a spot above it.
Life history: Males patrol for receptive females, who lay eggs singly on top of host plant leaves. Most feeding takes place at night. Young caterpillars chew holes in the tops of leaves, then later feed from the leaf tip. Older caterpillars eat half of the leaf before moving to the other half. Chrysalids overwinter.
Flight: Two-three flights in the north from June-October, 4-5 in the south from March-November.
Caterpillar hosts: Plants in the pea family (Fabaceae) including alfalfa (Medicago sativa), white clover (Trifolium repens), and white sweet clover (Melilotus alba).
Adult food: Nectar from many kinds of flowers including dandelion, milkweeds, goldenrods, and asters.
Habitat: A wide variety of open sites, especially clover and alfalfa fields, mowed fields, vacant lots, meadows, road edges.
Range: Southern Canada to central Mexico, coast to coast in the United States except for the Florida peninsula.
Comments: One of the most widespread and common butterflies in North America.
Conservation: Not required.
Management needs: Caterpillars can be very destructive in alfalfa fields.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Opler, P. A. and G. O. Krizek. 1984. Butterflies east of the Great Plains. Johns Hopkins University Press, Baltimore. 294 pages, 54 color plates. 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, 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.