Queen Alexandra's Sulphur (Colias alexandra W. H. Edwards)
Wing span: 1 5/8 - 2 1/4 inches (4.2 - 5.7 cm).
Identification: Upper surface of male bright yellow with pale yellow at wing bases; wings edged by narrow black border crossed by yellow veins; cell spot small. Female yellow, sometimes white, with forewing border faded or absent. Underside of hindwing of both sexes green-gray; cell spot white with no surrounding ring.
Life history: Males patrol open areas for females. Eggs are laid singly on top of host plant leaves, which the caterpillars eat. Late-stage caterpillars overwinter.
Flight: One flight from May-August.
Caterpillar hosts: Various plants in the pea family (Fabaceae) including milk vetch (Astragalus), Lupines (Lupinus), and clover (Trifolium) species.
Adult food: Nectar from flowers including blanket flower, milk vetches, and others.
Habitat: Road edges, fields, meadows, sagebrush flats.
Range: British Columbia south and east to eastern California, Arizona and New Mexico.
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.
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