Mountain Fritillary (Boloria napaea [Hoffmansegg])
Wing span: 1 3/8 - 1 7/8 inches (3.5 - 4.8 cm).
Identification: Outer margin of hindwing arched. Upperside of male orange with dark wing bases and delicate markings; female cream with heavy dark pattern. Underside of hindwing tan with faint markings.
Life history: Males patrol close to the ground during the day. Females lay eggs singly near host plants. Two years are needed to complete development from egg to adult; caterpillars hibernate their first and second winters.
Flight: One brood from late June-early August.
Caterpillar hosts: False bistort (Polygonum bistortoides) and alpine smartweed (P. viviparum).
Adult food: Flower nectar.
Habitat: Moist tundra and high mountain meadows.
Range: Holarctic. Alaska and Northwest Territory, western Yukon, northwestern British Columbia. Isolated populations in Canadian Rockies and Wind River Mountains of Wyoming.
Conservation: Not usually of concern but subspecies halli in the Wind River Mountains of Wyoming should be periodically monitored.
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: None reported.
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