ADULT TRICHOPTERA OF THE DEVIL-TRACK RIVER WATERSHED, COOK-COUNTY, MINNESOTA AND THEIR ROLE IN BIOMONITORING

Thirty two light trap collections of 7,797 adult Trichoptera made from 1990-1992, show that the Devil Track River Watershed in northeast Min nesota includes at least 16 families, 41 genera, and 101 species of ca ddisflies including three new state records: Agyrpnia colorata, Agrypn ia obsoleta, and Polycentropus glacialis. The greatest number of speci es were represented by the families Limnephilidae (21), Leptoceridae ( 19), Hydroptildae (13), Polycentropodidae (12), Phrygaenidae (10), and Hydropsychidae (9). Twenty two species were collected at all sites an d 46 at one or two sites. The greatest number of species (81) was coll ected from the Devil Track River and Devil Track Lake with fewer (64 a nd 40) from two sites on junco Creek. Most species are widely distribu ted and inhabit cool streams and lakes throughout eastern and northern North America. The high species diversity at all sites and the low nu mber of tolerant species indicate that water quality within the waters hed is good to excellent. However, increased water temperature, acidit y, and/or organic enrichment could adversely affect at least one third of the Trichoptera species inhabiting the Devil Track River Watershed .