Harford's Sulphur (Colias harfordii Hy. Edwards)
Wing span: 1 3/4 - 2 inches (4.4 - 5.1 cm).
Identification: Upper surface of male a rich yellow, wing bases not darkened. Cell spot in front wing is medium-sized and black, often with a white center. Forewing border wide, hindwing border narrower. Cell spot in hindwing not noticeable. Female resembles male but border less well-defined, in some cases reduced or lacking.
Life history: Males patrol open areas to find receptive females. Eggs are laid singly on the underside of host plant leaves; caterpillars eat leaves. Larvae hibernate.
Flight: Two flights from February-May and from June-August.
Caterpillar hosts: Rattleweed (Astragalus douglasii) in the pea family (Fabaceae).
Adult food: Flower nectar from thistles and mints.
Habitat: Open chaparral and woodland clearings.
Range: Southern California coastal ranges and canyons from Kern County south to San Diego County.
Conservation: Not usually required.
Management needs: Not reported.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
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.