Posted by
Andre on 24-08-2009 21:42
#3
This is a difficult one. But one thing first: forget
rotundicornis.
Rotundicornis is a synonym of
vernalis, as far as we know now.
Then... I think this might be
Ch. uviformis or
latifrons. But I am not sure enough, it's difficult based on pictures.
Posted by
Andre on 25-08-2009 08:39
#5
Damn, you are right! My mistake! I didn't read well, sorry, was reading 'ventris'!
Anyway.... I forgot that:
Rotundicornis =
uviformis 
It's a synonym never used anymore (the other former synonym for
uviformis =
argentifrons,

).
But all in all, we can conclude that your ID seems correct, with the restriction mentioned in my earlier posting.
Must say, that you made some perfect pictures, amazing!
Posted by
blowave on 28-12-2011 18:41
#7
Forgive me for bringing this thread back up, I have keyed a female which I had as C. uviformis. I know I have this species although it's relatively new to the UK, a male I had this year was identified as 99% certain by Martin Speight.
The Mark van Veen keys do not point to this female as being C. uviformis. Firstly, it depends on whether the wings are infuscated along the mid cross veins. If they are, this leads to Cheilosia caerulescens. I'm not sure if the face protrudes forwards on this specimen.
Secondly, if the wings are not infuscated on the mid cross veins, and the face does not protrude forwards (this I find confusing but it appears to be the 'cheek'

, the two options are whether or not the hind margin of the scutellum has bristles. I don't see bristles on this fly, this would lead to Cheilosia laticornis if the eye margin below the antennae has long white hairs.
If perchance it did have bristles on the hind margin of the scutellum (I can't see any) then it still does not appear to fit C. uviformis as the front and middle tarsus first segments should be pale.
Or am I missing something?

If it does have bristles, the alternative to C. uviformis leads to C. pagana and C. hercyniae.
Janet
Edited by
blowave on 28-12-2011 18:46