New aquatic insect (Ephemeroptera, Trichoptera, and Plecoptera) records for Alaska, USA: range extensions and a comment on under-sampled habitats

摘要

We report new records for eight aquatic insect taxa in Alaska, each representing a North American range extension. The new records, collected primarily from non-wadeable streams and lentic habitats, consist of four mayflies (Ametropus neavei McDunnough 1928, Caenis arnica Hagen 1861, C. youngi Roemhild 1984, and Labiobaetis dardanus McDunnough 1923), three caddisflies (Philarctus bergrothi McLachlan 1880, Sphagnophylax sp. and Triaenodes injustus Hagen 1861), and one stonefly (Malenka sp. Ricker 1952). Our surveys throughout Alaska suggest that the distribution and diversity of aquatic insects in non-wadeable streams and lentic habitats is poorly documented compared to that in wadeable streams. Samples from 85 lakes, ponds, and non-wadeable streams produced seven of the new records while samples from 450 wadeable streams produced only one (i.e., Malenka sp.). Further, our sampling shows that two of the taxa, C. youngi and L. dardanus, are common and abundant within their respective habitats throughout the geographic extent of our sampling.