Quite a distinctive looking fly with a pale 1st segment of abdomen.
Have added 2nd photo which shows the dark scutellum more clearly.
No interactions present.
Thanks Ian. Yes, happy with that. Also front legs 'extensively black' on tibiae & tarsi.
Have posted another odd fly on hogweed which is being very productive in this hot weather. Even has bumblebees coming to it which I think unusual.
Jamie from Briantspuddle
Lat/Lng: 50.7, -2.3
OS grid ref: SY8193