Seven of the 13 Minnesota Trichoptera species with official protected status were located in the state during 1997-2001, including four species – Agapetus tomus, Asynarchus rossi, Hydroptila novicola, and Polycentropus milaca – not collected in nearly 40 years. Three species – Chilostigma itascae, Oxyethira ecornuta, and Polycentropus milaca – appear rare in Minnesota, two – Agapetus tomus and Asynarchus rossi – appear rare but locally abundant, and two – Hydroptila novicola and Oxyethira itascae – were found throughout northern Minnesota suggesting that they are more abundant than previously thought. Five listed species were not collected during this study and are currently of unknown conservation status. One listed species, Setodes guttatus, almost certainly does not occur in Minnesota and should be delisted.
Houghton, David C. and Holzenthal, Ralph W.
"Updated Conservation Status of Protected Minnesota Caddisflies,"
The Great Lakes Entomologist, vol 36
Available at: https://scholar.valpo.edu/tgle/vol36/iss1/7