On a thistle (Cirsium sp) in one of the few remaining areas of grassland that hasn't been mown yet: gall fly Anomoia purmunda (Diptera: Tephritidae). When I first saw it, I thought it was two aphids standing on the back of a fly, and was quite surprised when the whole 'assemblage' flew off as a single unit.
A few metres away I came across the following, also on a thistle:
Photos taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2010-07-11.
Larvae and eggs of the green dock beetle, Gastrophysa viridula (Coleoptera: Chrysomelidae). Identification based on photos here and here. The larvae are demolishing this leaf so effectively that I don't think the larvae still in the eggs will find any left when they hatch out. For photos of the adults that I took last year, see here and here.
Photos taken in Whiteknights Park, Reading University grounds, Reading, UK, on 2010-06-15 and 2010-06-19, respectively.
The number and variety of Tephritidae this year has been quite spectacular, at least compared with last year. But, unfortunately, the stand of knapweed in the Wilderness has now been mown, so it might be a while before I come across any more new species there.
Photos taken in the Wilderness, Whiteknights Park, Reading University grounds, Reading, UK, on 2010-07-06.
On a recent walk I came across two of these small flies competing for the highest leaves on a bush in a woodland clearing. Initially I thought they might be Muscid flies based on their wing venation but at diptera.info Joke van Erkelens identified them as Anthomyiid flies of genus Pegomya (Diptera: Muscidae). Of the photos at diptera.info, the most similar is Pegomya pulchripes, but I am not going to claim that as an identification; there are lots of Pegomya species.
Photos taken in the Wilderness, Whiteknights Park, Reading University grounds, Reading, UK, on 2010-07-07.