Lonchaeidae (last updated: Jul 2024) In: In: Haenni J.-P., Bächli G., Bernasconi M., Dufour, C., Fisler, L., Gonseth Y., Lods-Crozet B., Monnerat C. & Pollini Paltrinieri L. (eds.) 2024. Diptera – Checklist.

European Lonchaeidae are small, stout-bodied, setulose acalyptrate flies (body length: 3-6 mm) with broad wings, body usually shiny blue-black; head wide and high; thorax broad; abdomen broad and flat; tibiae without strong setae; wing usually hyaline, occasionally slightly fumose but never patterned; halter invariably black. The single European species in the genus Lamprolonchaea Bezzi, 1920 (not yet recorded from Switzerland) has a metallic blue-green body colour. Lonchaeidae always have black halteres and lack setae on the shaft of tibiae, they superficially resemble some small Muscidae but are separable by the absence of a complete transverse suture on the mesonotum. They are sometimes also confused with Agromyzidae, but differ in having a longer cell dm (shorter than distal section of vein M in Agromyzidae) and with black, shiny species of Lauxaniidae but these have 2 pairs of lateral setae on the head and usually white halteres. Female Lonchaeidae with their sclerotized telescopic ovipositor have given rise to the vernacular name of the family « lance flies ».