Thread subject: Diptera.info :: Large Robber Fly

Posted by Basil Crowley on 23-08-2010 22:45
#1

I photographed this very large (~15mm) and fierce looking fly in my conservatory this morning. My best guess is that it is a female Regasilus sp. If anyone can give me a more authoritative and complete id, I would be most grateful.

Also any general information about the taxon would also be appreciated.

I have retained the specimen, in case more id info is needed.

Location: Oxfordshire, England.

Many thanks.

Posted by ChrisR on 23-08-2010 23:31
#2

With the tuft of hair on the underside of the tip of the abdomen it looks a bit more like Machimus atricapillus (if it still called that these days) :)

Posted by Basil Crowley on 24-08-2010 00:53
#3

Thanks for the reply, Chris. However, a search of this website for photos of Machimus atricapillus reveals no matches, so, as you surmise, this taxon name may not be current. I presume this is the same as Tolmerus atricapillus, photos of which do seem to bear a resemblance to the above?

So, would you agree that a male Tolmerus atricapillus, aka kite-tailed robber fly, would be the correct id/taxon name in this instance?

What else is known about it?

Posted by ChrisR on 24-08-2010 01:03
#4

Yeah, I just had a feeling that it had swapped genus since I last identified one! ;) atricapillus would be my guess, and it is incredibly common at this time of year, but perhaps a few of the real experts could chip in and help us out :)

I saw several this weekend at the Warburg NR, near Henley ... maybe you know the site? :)

Edited by ChrisR on 24-08-2010 01:03

Posted by Basil Crowley on 24-08-2010 01:22
#5

I see that there is a family forum for Asilidae. Perhaps I should have posted it there? :)

However, I am not confident about getting even the family right :o though I was very roughly on the right track this time. ;)

Posted by Quaedfliegh on 27-08-2010 20:22
#6

In the Netherlands it is still called Machimus but elsewhere the genus is now Tolmerus; so Tolmerus atricapillus is right. As for its size...for the sub family of the Asilinae it is pretty small ;)