Scenopinus jerei, a new species of window fly (Diptera, Scenopinidae) from Finland

A new species of window fly (Diptera: Scenopinidae), Scenopinus jerei sp. nov., with characteristic bi-coloured legs and completely black halteres, is described from Finland. To exclude potential previously named species, a survey of the relevant type specimens as well as original descriptions of the Palearctic and Nearctic Scenopinus species has been conducted, including old Scenopinus fenestralis (Linnaeus) synonyms. Scenopinus jerei sp. nov. is likely to be an overlooked, boreal forest specialist living in the nests of cavity- nesting birds. An identification key to the European species is provided.