Genus Laelius Ashmead, 1893

One species of this genus, Laelius microneurus, was reported previously from Britain and was keyed by Perkins (1976). Recent taxonomic work has shown that this species should be called L. femoralis (see below for discussion and synonymy). A second species, L. pedatus, is newly reported here from Britain. The two species may be identified from the key by Vikberg & Koponen (2005); a simplified key is presented here for the British species.

Key to females of British Laelius

1. Stigmal vein straight or almost straight, barely or not widened apically; pterostigma brown, slightly darker than basal vein, and without a seta which is longer than the nearby setae on the costal vein; apex of costal cell with several short setae; propodeum with discal longitudinal carinae slightly converging posteriorly; disc of fore wing hyaline (normally found outdoors) ……………………………………………………………………… Laelius femoralis (Förster, 1860)

- Stigmal vein curved and apically broadened; pterostigma as pale as basal vein and with dorsal seta which is longer than the nearby setae on the subcostal vein; apex of costal cell with 0(–1) small setae; propodeum with discal longitudinal carinae slightly diverging posteriorly, furthest apart at about posterior 2/3; disc of fore wing infuscate (normally found indoors) ……… Laelius pedatus (Say, 1836)