This chap was catching a few rays on the Buddleia or butterfly bush.
A Bing image search suggests it is:
Eristalis tenax, the common drone fly, is a common, migratory, cosmopolitan species of hover fly. It is the most widely distributed syrphid species in the world, and is known from all regions except the Antarctic. It has been introduced into North America and is widely established. It can be found in gardens and fields in Europe and Australia. It has also been found in the Himalayas.
Eristalis tenax is a large, stocky bee mimic. The eyes are marbled in black. Males have hovering displays. The average wing length is 9.75–13 mm and their average wingspan is 15 mm.
The exact appearance of the drone fly can vary considerably. The abdomen can vary in color from dark brown to orange. Pigmentation has an important role in the control of body temperature; the black areas down the center of the drone-flies abdomen may absorb solar radiation and so warm the dorsal blood vessel, which is right underneath.
and not a CIA espionage drone.
Though what are these three little red spots arranged suspiciously in a triangle?