Key and atlas to the genus Trichocera Meigen in Europe (Diptera, Trichoceridae)

The key presents all 59 species of the genus Trichocera MEIGEN which occur in Europe. Four subgenera are represented: Trichocera MEIGEN 1803 (five species), Metatrichocera DAHL 1967 (seven species), Saltrichocera KRZEMIÑSKA 2002 (35 species), and Staryia KRZEMIÑSKA & GORZKA 2016 (13 species). The type material of two species, one from North America and one from Asia, are described ( Trichocera columbiana ALEXANDER, 1927 and T . arctica LUNDSTRÖM, 1915), whose identities cause some problems and whose presence in the northern regions of Europe is possible. Two new species are described, Trichocera (Saltrichocera) longa , n. sp., and T . (Staryia) oulankae , n. sp. Trichocera versicolor is resurrected from synonymy; T. limpidipennis is synonymized with T . regelationis . There are separate keys to males and females; species are illustrated with camera pictures of diagnostic features: genitalia, antennae, and male tarsal claws, and additionally, wings and thoraces when only one sex is known, to enable further search. The state of knowledge of the genus in Europe and in the world is discussed.