Helina evecta

Keying this first to family and then to species (the latter using Mike Hackston's keys) was a long laborious process, but in the end it seemed to key reasonably smoothly (I'm sure it will get easier once I've done a few more muscids). The last-but-one couplet nearly had me lost as the light of the microscope made the hairs under the scutulum look pale which would have pointed to Helina trivittata, but the eyes were too hairy for that. Eventually I turned the fly around so the hairs weren't in the light, and lo and behold they were black!

male Helina evecta showing close up of scutulum, North Elmham Cathedral Meadows (Norfolk, UK), 6th March 2020

For this one my initial suspicion was that it would be another Helina evecta, and in the end I think it was. Once I'd got to Helina the path to evecta was easy, but there was a slight nagging doubt that I'd got the right genus. There were a few points in the keys (this time I also used the RES key) that weren't entirely convincing, so if anyone thinks I've messed either or both of these up please do let me know.

female Helina evecta, North Elmham Cathedral Meadows (Norfolk, UK), 8th March 2020

This one was in a pitfall trap. I used Mike Hackston's keys to ID it. The Muscidae key to subfamily and tribe split males and females but I couldn't see that it said how to sex them so I had to follow both options (once I'd got it to genus Helina the key to that genus does tell you how to separate males from females). The only other challenge I had was with identifying the lower orbital seta so as to decide if it was proclinate or not. If I identified the orbital setae correctly then most of them were broken off - there seemed to be stumps left but no setae.

female Helina evecta, Wendling Beck Environment Project (Norfolk, UK), 4th-5th April 2025