This rather distinctive fly completely stumped me yesterday but with the kind assistance from Ian Tew I am now able to name it as a Heather Fly (Bibio pomonae). Regularly seen throughout the day (13/6/12) and it seems that where it occurs it can be abundant. Same family as the St Mark's Fly (Bibio marci) and while I was searching for images of the Heather Fly on the net I found it to be quite a popular fly used in fly fishing.
