Alderflies

A pair of alderflies, Sialis sp (Megaloptera: Sialidae) mating.

Photo taken in Whiteknights Park, Reading, UK, on 2013-05-12.

Hoverfly

What I think is a female Melanogaster sp (Diptera: Syrphidae).

Photo taken in the field below Chazey Wood, near Caversham, UK, on 2013-05-11.

Tachinid Fly

A female Macquartia grisea (Diptera: Tachinidae).

Photos taken in the field below Chazey Wood, near Caversham, UK, on 2013-05-11.

Bibionid Fly

A male Dilophus febrilis (Diptera: Bibionidae).

Photo taken in the field below Chazey Wood, near Caversham, UK, on 2013-05-11.

Anthomyiid Fly

What I think is a female Anthomyia plurinotata (Diptera: Anthomyiidae).  This identification has been confirmed by Johanna van Erkelens here at Diptera.info. This species is apparently not on the UK checklist but it is on the Belgian one so it wouldn't be a big jump for it to get here.

Photo taken in Whiteknights Park, Reading, UK, on 2013-05-12