Diptera.info

Posted by Stephen R on 15-09-2009 11:33

Am I close? Last week, NW England. Oh, too hasty I think - just noticed only 3 PDC

Edited by Stephen R on 20-09-2009 15:43

Posted by andrzej grzywacz on 15-09-2009 14:58

Hmmm... acording to Gregor key, sometimes N. viridescens has only 3 postsutural dc on one or both sides. So I think it is corect. Nice, rare Neomyia :) Did anybody catch before specimen like this? I see this kind of viridescens for the first time.

Posted by Stephen R on 15-09-2009 18:13

Thanks for that, Andrzej:) I have some more photos at home which I think are of similar flies, so I'll count their bristles when I get back on Saturday!

Stephen.

Posted by Nikita Vikhrev on 15-09-2009 21:18

At my observations N.viridescens is rather common in late autumn (September is late autumn in Moscow region) either on flowers and on cow dung.

Posted by Stephen R on 15-09-2009 22:09

Since I am not a real dipterist I have been dividing my time rather unequally between flowers and cowdung:D, but I have seen these fairly often on flowers in the last two weeks. I think Andrzej just meant that it was rare to see them with 3 post dc.

Stephen.

Posted by andrzej grzywacz on 15-09-2009 23:10

Yes Stephen, acording to Gregor key i was thinking about N. viridescens with 3 post dc, "normal" viridescens I have observed many times :)

Posted by javanerkelens on 15-09-2009 23:21

3 postsutural dorsocentrals is possible...but rare
(F.Gregor,R.Rozkosny,M.Bartak & J.Vanhara)

Joke van Erkelens

Posted by Stephen R on 20-09-2009 15:40

I came home and looked at my later photos. I had a female (with normal 4 post dcs) and this male, which I am fairly sure is the same individual as the first image, but five days later. I thought it might be interesting to show the colour changes in a known timespan. I think it must have been quite fresh in the first image. Went out to look for it again today, but nothing but Lucilia turned up so far.

EDIT: Not the same - see below!

Edited by Stephen R on 07-10-2009 14:48

Posted by Stephen R on 06-10-2009 12:27

Here it is again on day 29. (First photo was Sept 7, this one Oct 5.) I found another photo from Sept 9 which shows that much of the change from blue to green happens in the first few days. The green - bronze transition seems to be much slower.

The wings are still as new; but like me it hasn't travelled very far B)

Posted by Stephane Lebrun on 06-10-2009 21:37

#10

The two last pictures clearly show Neomyia cornicina (presutural acr presnt and 3 post sutural dc).

Posted by Stephen R on 07-10-2009 14:46

#11

Ah, many thanks for putting me right Stephane! And now I see the difference in the scutellar bristles too. Must be more careful about jumping to conclusions!