A picture-wing fly. Looks close to Tephritis neesii, but not quite right.
No interactions present.
It does look like neesii. What was it on?
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
I agree - I'm sure it's neesii just with a little variation from the image in White (1988),
Thanks both. It was on Welsh Poppy, probably just a casual stop as it didn't hang around long. The thing that worried me was that it seemed to be outside the bounds of the variations I found online. But I couldn't find anything closer. I'll add a revision.
M. and Dave,
Just thought I should add, I only put 'It's likely to be this, but I can't be certain.' because I wasn't certain originally, not because I doubt your views! :)
Lat/Lng: 52.6, -1.2
OS grid ref: SK5501