North American Butterflies and Moths List

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Butterflies of North America

Scudder's Sulphur (Colias scudderi)
JPG -- species photo

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

Scudder's Sulphur (Colias scudderi)
distribution map
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