Colias philodice
Clouded Sulphur

Family Description:
Alternate Common Name: Common Sulphur.
Caterpillar: The caterpillar is typically bright green, but may be yellowish or even bluish green. It is striped lengthwise with darker green along the back, and white and pink along the sides.
Adult: This is a medium-sized to large butterfly, with a wingspan of 1 3/8 to 2 3/4 inches. Its appearance varies seasonally and between the sexes. The male is bright yellow on the upperside, possibly with a dark spot on the forewing and an orange spot on the hindwing; the wing edges are bordered by solid black. The female can be either greenish white or yellow on the upperside, with similar markings and a fainter border interrupted with yellow spots. Underneath, both sexes are marked with a row of blurred spots near the outside edge of the wings, a forewing spot, and a white hindwing spot outlined in pink. Early and late season adults may be paler and smaller.

This is a widespread species, which ranges from Alaska south and east across the southern half of Canada, and through most of the continental U.S. except for parts of California and Florida. It occurs throughout all of Idaho.

It can be found in many varieties of open areas, including meadows, fields, and pastures.


Caterpillar: Caterpillars eat the leaves of members of the pea family (Fabaceae), such as clovers (Trifolium spp.) and alfalfa (Medicago sativa).
Adult: Butterflies drink flower nectar.

There are generally three generations of caterpillars in the northern part of its range, and up to five in the south. The last brood of caterpillars of the season overwinters in a physiological state called diapause. Adults generally fly from May to October.

Males actively patrol for receptive females. Females lay eggs singly on the leaves of host plants.

Idaho Status: Unprotected nongame species.
Global Rank:

G5; populations are widespread, abundant, and secure.

Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.  Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.