Tetanura pallidiventris (Fallén) (Dipt. Scionyzidae) lives in terrestrial habitats in northern and central Europe, where the larvae feed on snails of the genera Cochlicopa, Discus, and Retinella. Field and laboratory data on the ecology and behaviour of the species are presented. The egg, third-instar cephalopharyngeal skeleton, and puparium are described and figured. The species is distinguished from T. fallenii Hendel, and the systematic position of the genus Tetanura Fallén is discussed.