Sun 2012-08-05 
A female Eristalis horticola (Diptera: Syrphidae). I suspect that the bright yellow patches on the side of the abdomen mimic the pollen stores on the legs of bees.
Photos taken in Whiteknights Park, Reading, UK, on 2012-08-02.
Sat 2012-08-04 
A male Tabanus sp, possibly Tabanus bromius (Diptera: Tabanidae). Note the horizontal line across each eye. Only the females bite.
Photos taken in the Wilderness, Whiteknights Park, Reading, UK, on 2012-08-02.
Fri 2012-08-03 
A small black soldier fly, probably a male Pachygaster leachii (Diptera: Stratiomyidae).
See here for a female.
Photo taken in the Wilderness, Whiteknights Park, Reading, UK, on 2012-07-28.
Thu 2012-08-02 
A male Tephritid fly, probably Chaetostomella cylindrica (Diptera: Tephritidae), on knapweed (Centaurea sp).
Note the everted pheromone sac on the side of the abdomen. The males use these to attract females.
Photos taken Whiteknights Park, Reading, UK, on 2012-07-28.
Wed 2012-08-01 
A female hoverfly, a Chrysotoxum verralli (Diptera: Syrphidae). Identification confirmed by Chris Webster here at Diptera.info.
Photo taken in the field below Chazey Wood, near Caversham, UK, on 2012-07-15.
