Isoperla transmarina

Isoperla transmarina (Newman, 1838) Notes Isoperla transmarina is commonly referred to as the Boreal Stripetail (Stark et al. 2012). This species is distributed in Canada from Newfoundland-Labrador west to British Columbia. In the USA, I. transmarina has been reported from Maine across the Laurentian Great Lakes region to Colorado and south to North Carolina (Szczytko and Kondratieff 2015, DeWalt et al. 2024). Harper et al. (1991 b) reported a univoltine-slow life cycle for this species in Quebec. Eggs hatched directly with larvae first appearing in June and July, followed by a two-week adult emergence beginning in mid-May. We report an adult flight period for I. transmarina in New York that extends from mid-March through late July (Fig. 38). Reported elevations for this species in the state range from 119-548 m asl (Fig. 39) with records primarily from larger streams and rivers in Level III Ecoregions Northeastern Highlands (58) and Eastern Great Lakes Lowlands (83) (Fig. 44 a).