Cylindromyia auriceps
This species is still only known in the UK from the 2 specimens Steve Falk picked up in the South Downs (I think!), though it is very common in southern Europe.
Key to the genus Cylindromyia
1. Hind tibia without posteroventral bristles [Scutellum with 3 pairs of marginal bristles; 9-11mm in length, abdomen without median discal bristles on segments 1+2, 3 and 4] …….. brassicaria (F.)
– Hind tibia with 1 or 2 posteroventral bristles ………………………… 2
2. Apical scutellars absent so 1 pair of scutellar bristles [6-8mm in length; abdomen with median discal bristles on segments 1+2, 3 and 4] ……………………….. interrupta (Meig.)
– Apical scutellars present so 2 pairs of scutellars bristles [8-10mm in length; abdomen usually with median discal bristles] ……………… auriceps (Meig.)