A male Epistrophe eligans (Diptera: Syrphidae). The golden thorax is the most obvious feature of this species. The abdomen varies from almost all black, as with this one, to an almost Syrhpus-like banding (see here). The males tend to be darker than the females.
Photos taken in the Wilderness, Whiteknights Park, Reading University grounds, Reading, UK, on 2012-04-01.