Psychoda sigma (formerly Psychoda surcoufi)
The only key I'm aware of for this family is the 1989 Dipterists Digest one by Phil Withers, but this only keys males to genus. However I made a breakthrough with this one by using the ObsIdentify app which was 100% confident that it wasw Psychoda sigma - with the important caveat that it wasn't in the geographical area covered by the app. Even without that major caveat, I would always want to check an ID delivered by this app, so I checked the key for the genus Psychoda. This DOES cover females, and although I didn't get to sigma directly using the couplets, the subgenital plates are illustrated and this appears to confirm the ID as sigma (given as surcoufi in the key).
, Cathedral Meadows, 7-May-21 (A) (1).jpg)
, Cathedral Meadows, 7-May-21 (A) (2).jpg)
, Cathedral Meadows, 7-May-21 (A) (3).jpg)
, Cathedral Meadows, 7-May-21 (A) (7).jpg)
, Cathedral Meadows, 7-May-21 (A) (6).jpg)
, Cathedral Meadows, 7-May-21 (A) (5).jpg)
, Cathedral Meadows, 7-May-21 (A) (8).jpg)
, Cathedral Meadows, 7-May-21 (A) (9).jpg)
, Cathedral Meadows, 7-May-21 (A) (10).jpg)
female Psychoda sigma showing close-up of an antenna, wing (top-lit and back-lit) and 3 views of the subgenital plate, North Elmham Cathedral Meadows (Norfolk, UK), 7th May 2021
This one wasn't keyed out but so far as I know none of the other species look quite like this. But I'm not certain that's true, so the ID is only presumed/probable.
 (1).JPG)
 (2).JPG)
presumed Psychoda sigma, Lizard (Cornwall, UK), 6th April 2017