Today I had a panicked phone call from a friend who said that she had a swarm of bees in her horse's stable. I have a friend who keeps bees so I phoned him and we shot up to her yard.
There were about 50 'bees' in two or three patches on her walls with individual ones coming and going all the time. My friend caught a couple and he confirmed that they were not, in fact, bees, but flies, in that they had a more bulbous head and only one set of wings. By now the flies were beginning to disperse and with a bit of help from some bug spray they cleared out. Once they'd left we could see that they had been laying little white eggs in clusters on the walls.
I have never seen behaviour like this from flies and was wondering if you could identify them for me? I have taken a couple of pictures of a dead one, with the 2p piece to give an idea as to its size.
I would in my ignorance (and distraction - the olympics are going on) and becuse the imgages are not clear, with certainty call it a Volucella pellucens. And now I revert to some ladies' basket game...
The only thing I will say is though, none of them were 'hovering' as I think of hover flies doing, and I've never seen them swarm like that - is that normal? Can't find anything about it on t'internet!