Nemoura trispinosa Claassen

was a recent addition to the Pennsylvania stonefly fauna based on one adult and numerous nymphs from one creek in Monroe County (Earle 2004a). In Pennsylvania, N. trispinosa appears to be limited to small, low gradient swampy creeks. Nemoura trispinosa is found from the Canadian Maritimes south to Pennsylvania and west to Manitoba and Wyoming.

New record: CLINTON: (S) Swamp Branch of Big Run, Haynes Township, 17 May 2004, late instar nymph (CM).