Taeniopteryx nivalis

Taeniopteryx nivalis (Fitch, 1847) Notes Taeniopteryx nivalis is commonly referred to as the Boreal Willowfly (Stark et al. 2012). This species has an unusual distribution in North America. In Canada, T. nivalis has been reported from mainland Newfoundland and Nova Scotia west to Alberta. In the USA, records extend from Maine west across the Laurentian Great Lakes region to Minnesota and Iowa and southwestward to Maryland and West Virginia. There is also a disjunct band from Idaho and Utah west to Oregon and Washington (Stewart 2000, DeWalt et al. 2024). Harper and Hynes 1972, Knight et al. (1976), and Sephton and Hynes (1984) have each reported univoltine-fast life cycles for T. nivalis nearly identical to that of T. maura. In New York, adults of T. nivalis are present from late February to the end of May (Fig. 22). This species is common in large rivers and streams ranging in elevation from 9-515 m asl (Fig. 23) and is widespread across the state (Fig. 25 b).