Tue 2012-03-06 
From a year and half ago: grey fly with yellow wing bases, probably Fannia lustrator (Diptera: Fanniidae). A male because the eyes almost touch on top of the head.
Photo taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2010-05-06.
Mon 2012-03-05 
From summer two years ago: a wasp, probably a tree wasp, Dolichovespula sylvestris (Hymenoptera: Vespidae). Identification based on the the excellent guide at Eakring Birds.
Photos taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2010-07-24.
Sun 2012-03-04 
Another Tephritid fly mating frenzy, this time of Terellia tussilaginis (Diptera: Tephritidae).
Photo taken in the Wilderness, Whiteknights Park, Reading University grounds, Reading, UK, on 2010-07-24
Sat 2012-03-03 
A mating frenzy of Tephritid flies Tephritis bardanae (Diptera: Tephritidae).
Photo taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2010-06-25.
Fri 2012-03-02 
A female Empid fly, probably Empis trigramma (Diptera: Empididae) judging by the 3 dark stripes on its back:
Photos taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2010-05-12.
