Malcolm wrote:
They are migrants from France which turn up in the southern half of
England almost every year, sometimes in quite large numbers, in whih
years they often reach further north into Scotland.

See, e.g., http://cgi.ukmoths.force9.co.uk/show.php?bf=1984

OK so there I was sitting by the pond feeding the fish when this beast came
along and hovered in front of me. Having never seen one before I was
somewhat apprehensive. (Strange things with stings worry me). First off I
thought it looked like a very fat damsel fly, but in the time I had to look
at it (not very long) I noticed its abdomen was about the size of a 13 amp
fuse, tan in colour and furry. Very rapid wing movements. Not much to go on
I know but all I was thinking was 'if that thing has a sting I could get
hurt' any ideas?

Steve R