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Boloria alaskensis alaskensis Moore, [1900]
Alaskan Fritillary; Angled Lesser Fritillaries
Family: Nymphalidae (Brushfoots)
Species account authors: Crispin Guppy and Jon Shepard.
Extracted from Butterflies of British Columbia.
Introduction to the Butterflies of BC
The Families of Lepidoptera of BC


© Jeremy Gatten     (Photo ID #6012)


Click on map to view a larger version of this map.
Distribution of Boloria alaskensis alaskensis in British Columbia.
(Click on the map to view a larger version.)
Source: Butterflies of British Columbia by Crispin Guppy and Jon Shepard © Royal BC Museum

Species Information


The Mountain Fritillary is easily recognized by the small size of the butterfly and the angled margin of the hindwings.

Immature Stages

Undescribed for North America.


The BC subspecies is the Alaskan Fritillary, B.n. alaskensis (Holland, 1900) (TL: Forty-Mile/Mission Creeks, AK). This subspecies ranges throughout all of Alaska except the northeast coast, central and southern YT, northern BC, and the Wilmore Wilderness Park area of AB.

Genus Description

The name Boloria is derived from the Greek bolos (fishing net) and refers to the reticulate or checkerboard wing pattern (Emmet 1991). The common name "angled lesser fritillaries" refers to their small size and to the angled margin of the hindwing. The common name is used here for the first time.

Palearctic workers and their popular books restrict the use of the genus Boloria to that of Warren (1944) and use a second genus, Clossiana, for most species in this group. We accept that approach. As used by Palearctic authors, the genus Boloria is defined by the shape of the valves. The dorsal or superior dorsal process has two distinct and heavily chitinized projections (Shirôzu and Yamamoto 1953). The genus Clossiana has only one (Warren 1944). Grey (1989) further points out that the uncus of Boloria is heavily spiculate or covered with short, thick hairs. In addition, the hindwing margin has a characteristic sharp angle at the M3 vein. Both Boloria and Clossiana have a bifid uncus, a tribal character. As defined by Palearctic workers, there are two to four species, only one of which occurs in North America.


The Mountain Fritillary flies from late June to early August, with peak flight in mid-July. There is one generation each year. Eggs are laid and hatch within 10 days (JHS). The overwintering stage is unknown. Vaccinium is the likely North American larval foodplant.


The Mountain Fritillary occurs in mountains across the northern fourth of BC and south in the Rockies into AB. Its habitat is moist meadows, usually along streams at or near timberline.



The Mountain Fritillary is found throughout AK, along the north coast of YT and NT to the west coast of Hudson Bay. It ranges south through central and southern YT to the AB Rockies near Adams Lookout, Wilmore Wilderness Park. There are also disjunct populations in the Wind River Range of WY. The species is Holarctic, occurring from northern Europe to northeastern Siberia.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)

BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

General References