Mead's Sulphur (Colias meadii W. H. Edwards)
Wing span: 1 1/2 - 2 inches (3.8 - 5.1 cm).
Identification: Upperside of male deep reddish orange with wide, dull black border; female lighter orange, border containing orange spots. Underside of both sexes greenish-yellow, with hindwing white spot circled in red.
Life history: Males patrol open tundra for females. Females lay eggs singly on host plant leaves, which are then eaten by the caterpillars. Third-stage caterpillars overwinter.
Flight: One flight from July-August.
Caterpillar hosts: Plants in the pea family (Fabaceae) including clover (Trifolium) and Astragalus species.
Adult food: Flower nectar including alpine sunflower and asters.
Habitat: At or near treeline in high mountains, tundra, subalpine meadows.
Range: Restricted to the Rocky Mountains from Alberta south to Colorado.
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.
References:
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