Hello, not sure how much traffic these boards get (its interesting that there is a black-fly appreciation group though!)
I was out taking photos in a local woodland to me (Croxdale Woods, County Durham) when I noticed a large red slug...was taking a few shots of it when I noticed a small fly that seemed to take a lot of interest in it. It stayed on its back for around 5 minutes and looked to be either tasting it or feeding from it.
I've posted this online in a couple of forums and people have confirmed that this is a blackfly - some said that it is unusual for them to feed from slugs, others said it was drinking the moisture from it.
Was wondering if anyone could shed some light on the matter? And possibly give a species identification and whether this one likes human blood? I don't think I have ever been bitten by a blackfly as far as I can remember, and I'm the kind of person that attracts horseflies, midges and mosquitoes from miles around!
Pete, Afraid I have been very lax in checking up on this message board. It is supposed to alert me whenever anyone posts a message, but that seems to have broken down. What a remarkable photo. Exceptional clarity, but not enough to identify it I'm afraid. It is certainly a female blackfly. They do take nectar and sugars from plants and from sap leaking from damaged bark. I guess this one is after any moisture it can get. The fact that its abdomen is not distended suggests that it is not feeding. Some species will feed on cold blooded vertebrates such as lizards and turtles. But I cannot find any records of feeding on slugs and snails. There is always a first! Thanks for posting