Diptera.info

Posted by Robert Heemskerk on 07-09-2006 16:18

hello flyforum,

I think this is a snail-killing fly.
What kind of snail-killing fly is it?
Is it a Coremacera sp.?

place: Amsterdamse bos / Amsterdam Forest

robert heemskerk

Posted by Robert Heemskerk on 07-09-2006 16:19

from the side

Edited by Robert Heemskerk on 07-09-2006 16:19

Posted by Nikita Vikhrev on 07-09-2006 16:49

Hi Robert.
I don't think it is Coremacera, 3-d antennae segment looks not hairy and wings very few spotted.
I'd say Elgiva (divisa?).
Nikita

Posted by Robert Heemskerk on 07-09-2006 19:13

Thank you for your reaction Nikita,

I have searched in the Dutch sp.list and found two types of Elgiva;

1. Elgiva cucularia (Linnaeus, 1767) [soort]
2. Elgiva solicita (Harris, 1780) [soort]

Then it will be Elgiva cucularia, when I have to choose..

And you have these spec. in your collection;
http://www.rosfoto.ru/shop/photo/47085/

;) robert,

Edited by Robert Heemskerk on 07-09-2006 19:14

Posted by Nikita Vikhrev on 07-09-2006 20:20

I think you are right, Robert. I've just found on first image strong mesopleural seta which I didn't find on second image.
Nikita

Posted by Tony Irwin on 07-09-2006 21:12

I think this is actually Psacadina, possibly zernyi, but I often have difficulty with these species.

Posted by Robert Heemskerk on 07-09-2006 21:31

This fly (Psacadina zernyi) occures also in the Netherlands and it is the only Psacadina sp. according to the Dutch species list.

It is not Elgiva cucularia?

robert,

Edited by Robert Heemskerk on 07-09-2006 21:32

Posted by Tony Irwin on 07-09-2006 21:51

It's not Elgiva cucularia because:
the posterior cross-vein is straight, not s-shaped
the costal cell (along the fore-margin of the wing) has a series of dark marks
the frons is not much more produced than the mouth margin
there is no mesopleural bristle! (the bristle on the first image is a notopleural)

Posted by Nikita Vikhrev on 07-09-2006 22:01

Tony, I dare to desagree with you.
I've never seen Psacadina but it has:
1. arista with long black hairs
2. no spines on apical part of hind femora (so hasn't Limnia)
3. strong mesopleural bristle isn't obligatory in Elgiva genus
Nikita

Posted by Jan Willem on 07-09-2006 22:08

#10

Hi,

It seems to me that the scutellum has only one pair of bristles, which would mean it is not Psacadina. What about Dichetophora?

Jan Willem

Edited by Jan Willem on 08-09-2006 13:36

Posted by Robert Heemskerk on 07-09-2006 22:25

#11

at least I see one black hair on the scutellum, so one pair of bristles is'nt strange at all.

I didn't know there where such a different type of (this kind of) snailflies :o

robert

Edited by Robert Heemskerk on 07-09-2006 22:25

Posted by Nikita Vikhrev on 07-09-2006 23:06

#12

There was some non-Elgiva smell indeed...
Thank you Jan, I think that Dichaetophora solve all troubles!
Nikita

Posted by Tony Irwin on 07-09-2006 23:37

#13

Good call, Jan! I'll go with Dichaetophora.

Posted by Robert Heemskerk on 07-09-2006 23:37

#14

It almost solve all troubles :D.., one step to go!;

According to the dutch specieslist there are two species:

1. Dichetophora finlandica Verbeke, 1964
2. Dichetophora obliterata (Fabricius, 1805)

Anyone who knows it, may solve it!

otherwise I am very satisfied already with these nice respondings..
thanks all of you!

Edited by Robert Heemskerk on 07-09-2006 23:40

Posted by Tony Irwin on 07-09-2006 23:44

#15

Judging from the drawings I have infront of me, I'd say yours is obliterata. But I have a little doubt. ;)

Posted by Jan Willem on 08-09-2006 22:17

#16

Dichetophora obliterata is known from the "Amsterdamse bos" according to Revier & Van der Goot (1989).

Jan Willem

Posted by Robert Heemskerk on 09-09-2006 13:11

#17

Jan Willem and Tony,

thank you very much for your help!

nice to see, there are earlier seeings of this fly in this area!

robert,

Edited by Robert Heemskerk on 10-09-2006 20:09