I found this 'beast' sitting rather clumsily on grass stems on a bank down at the back of the garden. This morning was rather overcast and much cooler of late, and I thought it may have been simply sunning itself. It seemed docile but menacing, with large exaggerated bronze waxy wings (reminiscent of the infamous 'cleg' fly) and a pair of beautifully sculptured black antenae. However, the eyes are completely wrong for this species. It's as big as a medium size bee and very hairy.
With the help of Google, I now know this to be a Hawthorn Sawfly, harmless and distributed over the British Isles but more common in the South. Once again, I'm always amazed what new discoveries we might find in our gardens. An hour later the fly had gone. Will we ever see one again? Who knows!