Small fly with brown wing markings. Coarse hair on thorax. Yellowish legs. c8mm.
No interactions present.
I think you have two species. The first pair as Orphys has identified look like T. formosa. The single fly looks as though it may be T. neesii.
Well spotted (like the fly)! I had foolishly assumed the second picture was the same species...but clearly not.
My Flickr photos...
Lat/Lng: 51.224166, 1.193705
OS grid ref: TR230520