Muscid Fly

A male Muscid fly, probably Helina evecta (Diptera: Muscidae).  Another possibility would be Helina annosa, as pointed out by Stephen R here, but according to the NBN Gateway data here and here, that species is much less common than H. evecta in the UK.

[Note added 2015-09-26: my experience collecting and identifying Muscid flies in 2014 and 2015 suggests that Helina annosa is actually quite common.  Hence it quite possible that the above fly is annosa.]

Photo taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2009-11-05.

Anthomyiid Fly

From back in the summer of 2009: a black and white anthomyiid fly, probably Anthomyia procellaris (Diptera: Anthomyiidae), based on my interpretation of comments by Michael Ackland here and here and by Joke van Erkelans here.  In particular, it is probably not A. pluvialis because in that species the black patch on the side of the scutum (top of the thorax) does not reach all the way down to the wing base.  The only other possibility in the UK would be A. bazini but that species is nowhere near as common as A. procellaris.

Photos taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2009-07-22.

Rust Fungus

An orange rust fungus, probably a Phragmidium sp, on the leaves of a blackberry bush (Rubus sp). 

Photo taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2009-05-01.

Black-Headed Gull

A non-breeding black-headed gull (Chroicocephalus ridibundus = Larus ridibundus).  Only breeding adults have the 'black' head, and even then it is really only dark brown.  The genus Chroicocephalus was recently split off from the genus Larus.

Photo taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2009-01-18.

Opetiid Fly

On foliage near a fungus-covered log: a small black fly, probably a male Opetia nigra (Diptera: Opetiidae).  O.nigra is the only UK species in the family Opetiidae, which was recently split off from the Platypezidae. 

The Opetia wing-vein pattern differs from those of the Platypezidae (see here, here, here, here and here).

Photos taken in the Wilderness, Whiteknights park, Reading University grounds, Reading, UK, on 2011-11-30.