Boloria frigga
Frigga Fritillary

Family Description:
Alternate Common Name:
Willow-Bog Fritillary.
Note: This species is referred to with the genus name Clossiana by some authors.
Caterpillar: The caterpillar is black and is marked lengthwise with a light purple line along each side.  The body is covered with black spines.
Adult: The butterfly is medium-sized, with a wingspan of 1 to 2 inches. The upperside is orange to light brown with a black cloudy region on the wings where they meet the body. The majority of both the fore- and hindwing is marked with black zigzags, with a row of black spots followed by a row of black dashes or "V’s" along the outside edge. The forewing tips are pointed. Underneath, the forewing is marked similarly but is paler. The underside of the hindwing is clouded with brown and has a white patch on the inside edge, perpendicular to the body; the outer half of the wing is light brown and has a curved row of brownish spots.

The species is holarctic, which means it can be found in the northern temperate regions of the entire Northern Hemisphere. In North America, it ranges from Alaska and northern Canada south to the Canadian border and into the northern sections of Minnesota, Wisconsin, and Michigan. There are also isolated populations in the Rockies, in central Colorado and in northeastern Wyoming. In Idaho, it has currently been documented only in Fremont County.

This is a species of bogs and arctic tundra.


Caterpillar: Caterpillars feed on the leaves of willows (Salix spp.), birch (Betula spp.), cranberry (Vaccinium spp.), and bog rosemary (Rosmarinus spp.).
Adult: Butterflies are known to visit flowers of Labrador tea (Ledum glandulasum), but only rarely.

There is one generation of caterpillars each summer. These caterpillars overwinter in a physiological state called diapause and then pupate in the spring. Adults generally fly from June to mid-July.

Males patrol the low portions of willow bogs for receptive females. Females lay their eggs on willows and are partly dependent on old beaver dams for the abundance of healthy willows at such sites.

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.