First records of Baetis vernus Curtis (Ephemeroptera: Baetidae) in North America, with morphological notes

Abstract

The Baetis vernus group (Ephemeroptera: Baetidae) – which includes B. brunneicolor McDunnough, B. bundyae Lehmkuhl, B. hudsonicus Ide, B. jaervii Savolainen, B. liebenauae Keffermüller, B. macani Kimmins, B. subalpinus Bengtsson, B. tracheatus Keffermüller & Machel, and B. vernus Curtis – is both diverse and taxonomically tangled. Some members of the group – B. brunneicolor, B. bundyae, and B. hudsonicus – have been previously found in North America. The remainder of the group is known to be only of Palearctic distribution, including B. vernus, which has a wide trans-Palearctic distribution. We report the collection of specimens from the Northwest Territories and British Columbia that we have identified as B. vernus using DNA barcoding and morphological examination and provide characters to assist separation of the North American members of the group from B. vernus. A genetically cohesive Holarctic clade for B. vernus likely relates to a Beringian dispersal event. This substantial expansion of the known range of B. vernus adds new phylogeographic and ecological complexity, but it may also help to provide further clues to the evolutionary history of this group.