Thread subject: Diptera.info :: Variation in Gymnosoma
Posted by Cor Zonneveld on 29-03-2009 13:49
#1
Here are three photos of Gymnosoma, all from Holland. When I looked at the first shown here, I saw a rather short stalk on the top cell. Moreover, the wings are a bit clouded. These features are different in the other photos. Is this normal variation, or did I overlook something?
First photo: Drents-Friese Woud, 2 August 2008. Boundary between mixed wood and meadow.
Posted by Cor Zonneveld on 29-03-2009 13:50
#2
This one is from het Gooi, the Netherlands, 25 April 2007. Long stalk on top cell, no cloud on wing.
Posted by Cor Zonneveld on 29-03-2009 13:52
#3
and yet another one. Noord-Limburg, the Netherlands; 9 June 2007.
Posted by Zeegers on 29-03-2009 14:33
#4
Interesting. The second looks like clavatum (note the formulation: looks like) and the third one might be clavatum as well. Need to study this.
Theo
Posted by ChrisR on 29-03-2009 15:08
#5
Cor Zonneveld wrote:
Here are three photos of Gymnosoma, all from Holland. When I looked at the first shown here, I saw a rather short stalk on the top cell. Moreover, the wings are a bit clouded. These features are different in the other photos. Is this normal variation, or did I overlook something?
I think you just highlighted the main problem with the genus - they are all very variable and no one feature is 100% reliable for each species. Sure females have more black on the abdomen but dusting is very variable always ... only some individuals will fit the keys perfectly :(