A revision of the Nearctic species of Liancalus Loew (Diptera, Dolichopodidae)

Abstract. The genus Liancalus Loew is revised for the Nearctic Region. Seven species are documented from this region including two new species: Liancalus genualis Loew, Liancalus hydrophilus Aldrich, Liancalus limbatus Van Duzee, Liancalus pterodactyl sp. n., Liancalus querulus Osten Sacken, Liancalus similis Aldrich, and Liancalus sonorus sp. n. Lectotypes are designated for the following species: Liancalus genualis, Liancalus hydrophilus, Liancalus querulus, and Liancalus similis. The species are illustrated, a key to males and females is provided, and their distributions mapped. Adults of Liancalus are some of the largest species of Dolichopodidae and commonly occur on waterfalls and vertical seeps.