St Marks fly?

arjw · #1 (**permalink**) 09-05-2010, 08:21 PM

Hello

First post and request for an id please. We've seen huge swarms of these in our local park..in the last few days. We think they are St Mark's fly - can any one help with a confirmation?

Many thanks in advance

Geoff F · #2 (**permalink**) 09-05-2010, 08:42 PM

Yes that does appear to be Bibio marci. But there are a few other variations of the Bibio species which can be difficult to identify from a rather small image.

Jason Green · #3 (**permalink**) 09-05-2010, 08:44 PM

Evening ARJW, and welcome to WAB!

It certainly looks like one. We have several of these, and only two species are actually truly called St. Mark's Fly. This appears to be one of the two, both of which have black borders to the wings as this one seems to have - or are they it's legs whilst washing? If they aren't the legs then it is either Bibio marci or B. hortulanus (Latin names) from what I can see. It's male, a tell-tale sign are the large eyes which it needs to find females for mating purposes.

Take care,

Jason

arjw · #4 (**permalink**) 09-05-2010, 08:51 PM

Many thanks for the quick reply Jason and Geoff.

Unfortunately we only had mobile phones to take the pic with

They seem to fly with their back legs dangling down and from what we've read that seems typical.

We'll have a closer look when we walk the dog tomorrow, if they're still swarming.

Thanks again.