Frigga Fritillary (Boloria frigga [Thunberg])
Wing span: 1 1/2 - 2 inches (3.8 - 5.1 cm).
Identification: Tip of forewing pointed. Wings orange-brown with black markings; darker at wing bases. Underside of hindwing with off-white patch near base of costal margin.
Life history: Males patrol in low areas of willow bogs. Hibernation is by nearly full-grown caterpillars.
Flight: One brood from late May-early August.
Caterpillar hosts: Cranberry (Vaccinium) and bog rosemary (Rosmarinus), perhaps willow (Salix) and dwarf birch (Betula).
Adult food: Flower nectar.
Habitat: Sedge and sphagnum bogs, arctic tundra.
Range: Holarctic. Northern Alaska and northern Canada east to Labrador, south to northern areas of Michigan, Minnesota, and Wisconsin. Isolated populations in Rocky Mountains to Wyoming and southcentral Colorado.
Conservation: Not usually of concern, but isolated populations may be of interest at the state or local level.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management needs: Maintain integrity of bog habitat.
Opler, P. A. and G. O. Krizek. 1984. Butterflies east of the Great Plains. Johns Hopkins University Press, Baltimore. 294 pages, 54 color plates. Opler, P. A. and V. Malikul. 1992. A field guide to eastern butterflies. Peterson field guide #4. Houghton-Mifflin Co., Boston. 396 pages, 48 color plates. 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
State and Regional References:
Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Nielsen, Mogens C., 1999. Michigan Butterflies and Skippers: A Field Guide and Reference. Michigan State University Extension, East Lansing, MI. 248 pp. Opler, P.A. 1998. A field guide to eastern butterflies, revised format. Houghton Mifflin Co., Boston.