Euphydryas editha
Edith’s Checkerspot

Family Description:
This species is referred to by the genus name Occidryas by some authors.
Caterpillar: The caterpillars vary in appearance, but generally are black and may be marked with stripes or spots of white or orange. The body is covered with black spines which may be colored orange at the base.
Adult: The butterfly is small to medium-sized, with a wingspan of 1 1/8 to 2 inches. Like the caterpillar, it can vary in its appearance. Typically, the upperside is dark brown to black and marked with red, orange, yellow and white spots or squares. The spots are arranged in bands broken up with black. Often, there is a band of red along the outer edge, followed by one or two rows of yellowish white dots. Underneath is marked with bands of yellow, orange, and offwhite outlined and broken up with brown.


This species ranges from southern British Columbia and Alberta south to southern California, Nevada, Utah, and Colorado. In Idaho, it occurs throughout most of the state.


It utilizes a variety of habitats, such as tundra, grasslands, open woodlands, sagebrush steppe, and chaparral along the coast.


Caterpillar: Caterpillars feed on the leaves and flowers of a number of plant species, including Indian paintbrush (Castilleja spp.), lousewort (Pedicularis spp.), and plantain (Plantago spp.).
Adult: Butterflies feed on flower nectar.


Young caterpillars live in webs made of loose silk. There is one new generation of caterpillars each summer. Older caterpillars overwinter, often under rocks, in a physiological state called diapause. They may switch the host plants they feed on after they emerge in spring. Adults generally fly from March through late August.


Males perch and actively patrol in search of receptive females. Females lay eggs in groups on the underside of leaves or on flowers of host plants.

Idaho Status: Unprotected nongame species.
Global Rank:

G5; most populations are widespread, abundant, and secure. Certain subspecies in California, however, are listed as T1, which means each is critically imperiled because of extreme rarity and is imminently vulnerable to extinction.

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.