---

Very small fly on the window, 24/11/2020 (Spain: Girona: Catalonia: Beuda).

Identification following Marshall & Richards in McAlpine et al 1987 Manual of Nearctic Diptera to Leptocera, but then stopped as arriving to a cul-de-sac (as there are some genera missing in that key, present in Spain, Carles-Tolrà, 2002).

Wing apparently functional;
halter with knob
Cell cup open to wing margin, CuA2 absent, and cell bm confluent with cell dm;
CuA1 never reaching wing margin, except as a weak fold.
LIMOSININAE

Disc of scutellum bare.
Margin of scutellum always bare between apical bristles
Mid tibia with a long preapical ventral bristle

Mid tibia with an apicoventral bristle
Scutellum with six marginal bristles (so it's not Peremis fenestralis)
Leptocera Olivier (four subgenera).