Tachinid Flies

A pale-faced black Tachinid fly, probably Exorista rustica (Diptera: Tachinidae).  Similar to Voria ruralis but the hairs between the eyes are arranged in two neat lines down the face.

Here is a side view of one from a couple of months earlier:

Photos taken in Whiteknights Park, Reading, UK, on 2010-07-30 (top) and 2010-05-30 (bottom).