Survey of Chironomidae (Insecta: Diptera) from the Kuskokwim River Watershed in Western Alaska

Rapidly declining diversity of freshwater species necessitates surveys to document and describe patterns in biodiversity. To this end, a survey of Chironomidae (Insecta: Diptera) was conducted in a remote watershed of western Alaska. Larval chironomids were collected from 16 stream sites in the Kuskokwim River watershed in 2009 and 2010. Twenty-seven chironomid taxa were identified. Orthocladiinae was the most diverse subfamily and was numerically dominant at all sites except a glacial runoff stream where Diamesinae was numerically dominant. Two rare chironomids were collected in the study: an undescribed species of Stilocladius and a species of Orthocladius (Mesorthocladius). The latter genus has only 2 described species in North America, one in Ohio and one in Minnesota. Results of a nonmetric multidimensional scaling analysis indicated that sites varied based on changes in elevation, conductivity, pH, and percent Diamesinae. Two high-elevation sites, one at the outflow of a lake and the other...