I have searched endlessly for an ID on this fly, found nothing. As you can see, it was feeding on blackberries back in September. I had forgotten to post it.
It had totally black body and wings apart from the bright yellow abdomen which had a broken black stripe on the underside.
I'd have taken some more shots and better ones if it hadn't been for the 30-off cows that charged me only seconds later!!

I survived..by escaping through a bog in the next field.

Scared the life out of me. They poked their heads through the bushes mooing loudly at me whilst I made away with an enormous stash of blackberries!
I digress..anyone know what this creature is? I am baffled.
Many thanks all!!