Dingy Fritillary

Boloria improba is a resident of far northern Canada; in the west it ranges as far south as mid-British Columbia. There are also two small independent populations in mountains of Colorado and Wyoming (Scott 1986). Habitats are Arctic/Alpine zone tundra, in moist places with a carpet of dwarf willow. Host plants are tiny herbaceous species from one genus, Salix (Salicaceae). Eggs are laid on the host plant singly. This species is biennial; individuals overwinter as newly hatched larvae the first winter, and as unfed fourth-stage larvae the second winter. There is one flight each year (even years in Alberta) with the approximate flight time late June-July31 (July15-early Aug in Colo; Aug1-15 in Wyo) (Scott 1986).

Adults sometimes sip flower nectar, often get moisture by sipping from soil. Males patrol for females (Scott, 1986).

Not of concern.

Biennial, flying during July of even-numbered years.

Alaska to Baffin Island, south to west-central Alberta. Isolated populations occur in Wyoming and Colorado. Also found in Scandinavia and Siberia (Scott 1986).

"The upperside is a smudged, brown and dull orange. The hindwing underside markings consist of a yellow-tan median band and pale whitish costal patch on purple-brown background. The small size and dull appearance distinguishes this species from other Boloria. Our populations are subspecies nunatak (Scott 1998). "

Moist, willow-rich alpine tundra.

The immature stages are undescribed. Colonies of this butterfly tend to be very localized, and adults have a weak, ground-hugging flight.

The larval host plants are unreported in Alberta; Dwarf willows such as Salix reticulata nivalis are used in Colorado (Scott 1986). Adults nectar at Moss Campion (Silene acaulis) and yellow composites in Alberta (Bird et al. 1995).