Columbian Snowfly - Utacapnia columbiana
State Rank Reason (see State Rank above)
The Columbian Snowfly is currently ranked "S2" in Montana because it was thought to be at risk due to very limited and/or potentially declining population numbers, range and/or habitat, making it vulnerable to extirpation in the state.
Species within the Capniidae are small winter stoneflies. This family is one of the largest families in the order Plecoptera, containing some 300 species distributed throughout the Holarctic region; 25 species occur in Montana. As their name implies these species are generally cold-water stenotherms and hatch in late-winter through early spring. The adults emerging in the winter are often found walking around on the snow. Their closest relatives are the Rolled-winged Stoneflies (Leuctridae). Many species are endemic to small ranges, perhaps due to the family's tendency to evolve tolerance for cold (isolating populations in mountain valleys) and winglessness (inhibiting dispersal).
It occurs in the northwestern Nearctic from Montana and northern California to Alaska into Alberta and the Yukon (Stewart and Oswood, 2006). Gaufin et al. (1972) cite Montana distribution as the Kootenai River in Lincoln County Newell et al. (2006) report it infrequently from the Flathead River basin in western Montana.
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Records indicate that this species inhabits both cold mountain streams and rivers.
Merritt and Cummins (1996) report that members of this family are trophically shredder-detritivores; eating large particulate organic materials such as detritus, leaves and plants.
Adults are flying in March to May.
Threats or Limiting Factors
Listed as a rare species when found, never abundant. Larvae cannot be identified to species and adults are rarely collected by biomonitoring agencies, thus few records exist.
- Literature Cited AboveLegend: View Online Publication
- Merritt, R.W. and K.W. Cummins. 1996. An introduction to the aquatic insects of North America. 3rd Edition. Kendall/Hunt Publishing Company. Dubuque, Iowa. 862 pp.
- Additional Sources of Information Related to "Insects"