E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Boloria eunomia Reuss, 1920
Bog Fritillary; Lesser Fritillaries
Family: Nymphalidae (Brushfoots)
Species account authors: Crispin Guppy and Jon Shepard.
Extracted from Butterflies of British Columbia
The Families of Lepidoptera of BC
Introduction to the Butterflies of BC
Photo of species

© Norbert Kondla  Email the photographer   (Photo ID #74019)

E-Fauna BC Static Map
Distribution of Boloria eunomia in British Columbia
Details about map content are available here.

Species Information


The Bog Fritillary is easily distinguished by the ventral hindwing. The postmedian row of spots are an even row. The spots are almost perfect circles, cream-coloured and edged with black. Subspecies C.e. nichollae is a dark form from high elevations in the Rockies.

Immature Stages



The BC populations are the widespread boreal subspecies C.e. dawsoni (Barnes & McDunnough, 1916) (TL: Hymers, ON). The subspecies C.e. nichollae (Barnes & Benjamin, 1926) is currently known only from near the Columbia Ice Field in Alberta, but adjacent habitat in BC is totally unexplored and the subspecies may be found in BC. Nichollae's Fritillary seems to be genetically distinct, not just a high-elevation form.

Genus Description

Reuss (1922) stated that he named the genus Clossiana for the recognized entomologist Herr Adolf G. Closs, but it appears that Closs was only a minor worker on Lepidoptera. The common name "lesser fritillaries" refers to the small size compared with Speyeria.

Under the restricted generic usage of Boloria, we state why we recognize the genus Clossiana and define the genus. On the upperside, the wings are very similar to those of Speyeria. Some males of one species of Speyeria, S. mormonia, are as small as the largest females of our largest Clossiana, C. tritonia. Only one species, Clossiana selene, has silver spots on the ventral hindwing. This genus is Holarctic, with at least 21 species; 13 are found in North America and 12 of these occur in BC. Nine BC species are Holarctic. The 4 temperate species, 3 in BC, feed on violets (Viola) but the northern species do not. There has been much confusion in the literature regarding larval foodplants, and we discuss only those verified by Shepard (1975) and later.


The Bog Fritillary is one of four species found together in high mountain habitat in the Rocky Mountains and boreal habitat across Canada. It is the third of the four species to emerge, after C. freija and C. frigga, and before C. chariclea. It is presumed that the peak flight of the four species is staggered to avoid interspecific matings (JHS). There is much comment in the literature that this species has a very short adult flight period, but such is not the case in western Canada. Mark-release-recapture studies by Shepard (JHS) showed that the Bog Fritillary had a flight period of normal length and was equal to C. chariclea. The flight is from mid-June to early August with a peak in early July, depending on elevation and high-elevation snow cover.


The Bog Fritillary is found east of the Coast Ranges in the northern half of BC and in the Rockies along the AB border. The habitat is spruce forest meadow openings along streams, and around the fringes of bogs and small, mature glacial lakes at the southern edge of its distribution.



The Bog Fritillary is found from AK and across most of CAN except the Canadian archipelago, southern BC, and the southern prairies. In the lower USA, it occurs only just south of Lake Superior and in disjunct populations in WY and CO. The species is Holarctic, occurring in northern Europe and across non-arctic Russia.

Status Information

Scientific NameOrigin StatusProvincial StatusBC List
(Red Blue List)
Boloria eunomiaNativeS5YellowNot Listed
Boloria eunomia dawsoniNativeS5YellowNot Listed
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Synonyms and Alternate Names

Clossiana eunomia

Additional Photo Sources

General References

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-07-13 7:27:24 PM]
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