Revision of European Elachistidae. The genus Biselachista Traugott-Olsen & Nielsen, 1977, stat. rev. (Lepidoptera: Elachistidae).

The genus Biselachista Traugott-Olsen & Nielsen, 1977, with a Holarctic diffusion and represented in Europe by seventeen species living in various environments, from sea level to 2000 metres in the Alps, is considered a valid genus. The biology of some species is well known thanks to laboratory rearings. Their host plants and parasites are reported. The pre-imaginal stages and the male and female genitalia are illustrated. The currently ascertained distribution is given. The examination of the type material permitted to ascertain the following synonymies: Biselachista occidentalis (Frey, 1882) is a synonym of Biselachista juliensis (Frey, 1870); Elachista saarelai Kaila & Sippola, 2010 is a synonym of Biselachista kebneella Traugott-Olsen & Nielsen, 1977. KEY WORDS: Lepidoptera, Elachistidae, Biselachista, biology, genitalia, distribution, Europe.