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Boloria improba youngi Reuss, 1920
Lesser Fritillaries; Young's Fritillary
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


© Ian Gardiner     (Photo ID #5751)


Click on map to view a larger version of this map.
Distribution of Boloria improba youngi 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 Dingy Fritillary is our smallest fritillary. It is very similar to the Frigga Fritillary in wing pattern, but the two never fly together.

Immature Stages

Undescribed except for the disjunct subspecies C.i. acrocnema Gall and Sperling, 1980 of Colorado and Wyoming. Scott (1982) described the immatures in detail. The egg is tan. The head of the mature larva is dark brown. The body is brown with various lighter and darker lines and a conspicuous cream dorsal line. The tubercles or scoli are reddish brown.


The BC subspecies, Young's Fritillary, C.i. youngi (Holland, 1900) (TL: Forty-Mile/Mission Cr., AK), occurs in central Alaska, central and southern Yukon, and across northern BC, just entering Alberta in the Rockies south to Hinton.

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.


Dingy Fritillaries fly from early June in the far north to early August in the Rockies, with peak flight in mid-July for all populations. There is one generation per year. Scott (1982) reared the species on Salix reticulata nivalis. In BC it is always found on ridges above timberline in association with similar dwarf willows that barely grow above ground to avoid the cold winds of the habitat.


The Dingy Fritillary is found in the northern half of BC only above timberline in alpine tundra.



The Dingy Fritillary ranges from AK east across arctic and alpine CAN, including the southern Canadian archipelago to Baffin Island but not Labrador. There are two disjunct populations, one in Wind River Range, WY, and the other in the San Juan Mountains, CO. The species is Holarctic, occurring in the far north of Norway and Sweden and the far north of Russia to eastern 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