Thread subject: Diptera.info :: Sphaeroceridae ?

Posted by Ben Hamers on 08-08-2006 22:42
#1
Hello,

This rather small (2 mm) fly I saw in Southern Limburg (Kunderberg) in July.

Ben
Edited by Ben Hamers on 21-05-2012 20:34

Posted by Tony Irwin on 08-08-2006 22:54
#2
Not Sphaeroceridae. I'd try Milichiidae.

Posted by Paul Beuk on 09-08-2006 07:13
#3
Hmm, what genus would you suggest in that case?

Posted by Tony Irwin on 09-08-2006 10:10
#4
Madiza? Frown

Posted by Paul Beuk on 09-08-2006 10:30
#5
I wondered about that one, too, but in my experience 2 mm is may be on the small side and when I compare this image to the one on http://www.sel.ba...ma-ga.html, I think the head may be too flattened in the specimen illustrated here.

Posted by Tony Irwin on 09-08-2006 10:59
#6
Seguy gives the size as 2.25 to 2.5mm, so I think Ben's estimate is near enough. I agree the head shape looks a little flat compared to Brake's photo, but that is actually dorso-lateral (both antennae are clearly visible), rather than strictly lateral, as in Ben's photo. This could explain the difference. Tomorrow I hope to compare specimens to the photo (I haven't got any at home), so we should be able to resolve it then.
I note that Fauna Europaea does not record any Madiza from the Netherlands. Is this another reason for your doubt? Wink

Posted by Paul Beuk on 09-08-2006 12:35
#7
Nope, that is just omission ar Fauna Europea. It is quite common if you know how to look for it.

Posted by Jan Willem on 10-08-2006 07:09
#8
I asked Irina Brake (http://www.sel.barc.usda.gov/Diptera/milichid/mi-home.html) to give her opinion.

Irina wrote:
I would say it is Madiza glabra. You can see the different structure at the base of T5, which is due to some glands.


So Tony, it seems you are totally right!

Jan Willem

Posted by Tony Irwin on 10-08-2006 09:43
#9
This morning I compared the photo to some (rather old) specimens of Madiza glabra, and it matched very well. Among the features which seem characteristic - the sphaerocerid-like head shape with flat frons, the chunky legs, the milky wings, the long bristles at the end of the abdomen, and the shining black haltere. This last feature (visible in front of and slightly below the white flash spot at the base of the abdomen) is rarely found - the halteres of most flies are white, yellow or brown.
But exactly which species of Madiza this is ...? I suspect we may need the specimen.
Edited by Tony Irwin on 10-08-2006 09:43

Posted by Paul Beuk on 10-08-2006 09:54
#10
So far from the Netherlands only glabra has been recorded.

Posted by Ben Hamers on 10-08-2006 18:55
#11
Hi,

Many thanks to you all for this multinational and intercontinental action to identify this fly.
I have seen flies like this at several occasions sitting on the top of posts. Next time I will try to make a better picture for the gallery.

Ben

Posted by Tony Irwin on 10-08-2006 20:47
#12
Paul - I have to confess I've never caught this fly knowingly. You suggest there is a good way to look for it. Is this examining the top of posts, as Ben does, or are you thinking of something else? TIA.

Posted by Paul Beuk on 11-08-2006 07:19
#13
One of the ways to collect it is to look indoors, for example, in appartment buildings where windows are open on warmer days. Especially in parts of the buildings where staircases have lots of glass and opened doors you can find them on windows.
Otherwise posts or bare trunks can yield specimens but that is more accidental, I think. I know I have also seen quite a lot of specimens in Malaise traps.