Hoverfly

A male Sphaerophoria scripta hoverfly (Diptera: Syrphidae).

Two features mark it out as a male: firstly the large eyes which meet at the top of the head (in females there is a gap between the eyes), and secondly the long straight-sided, blunt-ended abdomen which extends well beyond the tip of the wings when they are folded (in females the abdomen is fat in the middle and tapers to a point at the tip).

According to Michael Chinery (Complete British Insects, Collins, 2005), in S. scripta "There is always a yellow stripe on each side of the thorax but the abdominal markings vary a great deal".  As an illustration of the latter point, compare the above photo with the one here.

Photo taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2009-07-25.