Dingy Fritillary (Boloria improba) (Butler, 1877)

Diagnosis: This small (wingspan: 28 to 34 mm) fritillary appears quite dark on the wing. The brown upperside of the wings have indistinct dark bands and a dark base. The lighter brown underside has a wide greyish band covering the outer part of the hindwing. There is also a distinct white mark along the leading edge of the hindwing, like that in bellona.

Subspecies: Only the nominate subspecies is found in Canada.

Range: This butterfly has a wide range in the Northern Hemisphere. It is found in northern Europe and Asia. In North America, it is mainly Canadian, but is also found in Alaska and there are isolated populations in Wyoming and Colorado. In Canada, it flies in the western Arctic, from Alaska east to southern Baffin Island (also on Nottingham Island close to Quebec) and north to Melville Island. It ranges south into western British Columbia and in the Rocky Mountains south to Prospect Mountain near Cadomin, Alberta.

Similar Species: Boloria improba looks like a small, dingy form of the Frigga Fritillary (B. frigga). [compare images]

Early Stages: These are unknown in North America, but larvae are known to feed on a dwarf willow (Salix herbacea) in Europe.

Abundance: This butterfly is locally common.

Flight Season: The Dingy Fritillary flies in late June and July depending on latitude and altitude.

Habits: This is strictly a butterfly of arctic tundra and moist alpine regions. It flies slowly, very low to the ground and spends much of its time in wet depressions in the tundra that are covered with short grass-like sedges. Its dark colour is an adaptation to the cool, short summers where it is found. JDL has seen this species on the wing at 1 a.m. in northern Yukon when the sun is low on the horizon.

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.