Euchloe ausonides
Large Marble
Family:Pieridae
Family Description:
Alternate Common Names:Large Marble White, Dappled Marble, Ausonides Marble, Creamy Marblewing.
Description:
Caterpillar: The caterpillar is dark green to bluish gray and marked lengthwise with yellow and white stripes along the back and sides. It is covered with tiny black dots, and reaches a maximum length of � inch.
Adult: The butterfly is medium-sized, with a wingspan of 1 � to 2 inches. It is white on the upperside, with the interior of the wings shaded with black close to the body. The forewing is tipped with black to brown and spotted with white; there may be a single, dark crescent-shaped spot near the edge. The hindwing is offwhite, and the marks on its underside slightly show through. Underneath, the forewing is white with yellowish tips and marked similarly to the topside. The underside of the hindwing is marbled with thick lines of yellowish green to brown, and has noticeable yellow veins.

Range:
This is a butterfly of primarily western North America, ranging from central Alaska south to California and northern Arizona and New Mexico, and east to the western portions of the Plains states, and to northern Minnesota and southwestern Ontario. It occurs through most of Idaho.

Habitat:

It can be found in open, often moist areas, including fields, meadows, and open forests.

Diet:

Caterpillar: Caterpillars eat the buds, flowers, and fruits of members of the mustard family (Brassicaceae), such as rock cress (Arabis spp.) and various mustards (Brassica spp., Descurainia spp., and Sisymbrium spp.).
Adult: Butterflies drink nectar, most often from yellow or white flowers of their host plants.

Ecology:

There is one generation of caterpillars per growing season through most of its range, but there may be two in California, the first of which occurs in early spring. Pupae overwinter in a physiological state called diapause. Adults generally fly from late April through August.

Reproduction:

Males actively patrol to find receptive females. Females lay eggs singly on the flower buds of host plants.

Conservation:
Idaho Status: Unprotected nongame species.
Global Rank:

G5; populations are widespread, abundant, and secure.

References:
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. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (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.