Scudder's Sulphur (Colias scudderi Reakirt)
Wing span: 1 1/2 - 2 inches (3.8 - 5.1 cm).
Identification: Upper surface of male lemon yellow; dark wide border cut by yellow veins. Females often white, with small black cell spot; border incomplete or lacking. Underside of both sexes dirty green.
Life history: Males patrol near willows for receptive females. Females lay eggs singly on young host plant leaves. Caterpillars eat leaves. Second-, third-, and fourth-stage caterpillars hibernate.
Flight: One flight from late June-August.
Caterpillar hosts: Willow shrubs in the willow family (Salicaceae).
Adult food: Flower nectar.
Habitat: Mountain meadows and willow bogs.
Range: Alaska south through Rocky Mountains to northern New Mexico.
Conservation: Not usually required.
Management needs: Not reported.
The Nature Conservancy Global Rank: G4 - Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery.
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.