This fly (wing length 7 mm) came from mixed woodland in south Hampshire, at MV light on 14th August 2020. It keyed to Heleomyzidae, and had most of that Family’s characteristics – but not all. It has no F-bristles, and the frons is very narrow. There are two sizes of bristle along the costa, but the difference between the long and short ones isn’t great.
Features not shown in the photo include pro-sternum bare; pre-apical dorsals on tibiae; a large ventral apical on the mid-tibia; a pair of converging P-bristles. There are no hairs below the scutellum and the form of the genitalia is very un-anthomyid. Meron bare. If its deficiencies as a heleomyzid are ignored, it would run to Heteromyza oculata, which it obviously is not.
I’m disappointed that I can’t work out even what Family it belongs to, and would appreciate a nudge in the right direction, please.
Why do you feel it's not Heteromyza oculata?
Thanks, Tony, a good point. It was 'obviously' not H. oculata because it was obviously not the same as my two reference specimens - about twice the size for starters. However one of my reference specimens is probably H. commixta/rotundicornis, and the other is teneral, and both are females. There is still the problem that it has no frontal bristles, and should, according to the test key, have at least one. However I've seen one image on-line with a narrow frons and no frontal bristles. It looks as though it is H. oculata then!
Thanks again for coming to my help - not for the first time!
I'd love the record details for the Heleomyzid Recording Scheme please.