Tachinid Flies

Tachinid fly Ramonda spathulata (Diptera: Tachinidae).  The metallic greenish-grey body and the triangular shape formed by the wings at rest are characteristics of this species.  Also note the big forward-pointing spines on the middle tibiae.

The individual in the above two photos was probably a female.  In the following photo of a mating pair the male, though somewhat out of focus, seems to have a slightly narrower gap between the eyes on the top of the head:

Photos taken in Whiteknights Park, Reading University grounds, Reading, Uk, on 2012-04-06.