Thread subject: Diptera.info :: Dolichopodidae Rhaphium? > cf. Chrysotus sp.

Posted by blowave on 27-12-2010 23:52
#1
Hello,

I don't think I can find the species name, but is a genus possible?

15th June, my garden near Lincoln UK. Size ~4mm

Thanks!

Janet :)
Edited by blowave on 28-12-2010 20:41

Posted by blowave on 27-12-2010 23:54
#2
pic 2

Posted by rvanderweele on 28-12-2010 00:03
#3
pretty fly. For me not enough details.

Posted by blowave on 28-12-2010 00:09
#4
It was one of those which the camera did not like! I might have another pic later, I think I see this one every year. :P

Posted by Jason G on 28-12-2010 01:01
#5
I think the process of deduction starts with wing venation (unless anyone are familiar with the gizz of this one), so any with that would be good.
Edited by Jason G on 28-12-2010 01:05

Posted by blowave on 28-12-2010 01:52
#6
Jason G wrote:
I think the process of deduction starts with wing venation (unless anyone are familiar with the gizz of this one), so any with that would be good.


Not always wing venation with these Jason, if I could have found a genus using the key I might have been closer. I am relying on jizz, if anyone does happen to recognise it. I don't think there's enough detail to use the key. Take a look at Igor's keys..

http://www.fortun...Genera.htm

Posted by Stefan Naglis on 28-12-2010 13:59
#7
Looks like Chrysotus sp.

Posted by Jason G on 28-12-2010 15:07
#8
Stefan Naglis wrote:
Looks like Chrysotus sp.


Ah; you see I edited my post? I removed my suggestion of Chrysotus sp., so glad someone else has gone that far.

Posted by blowave on 28-12-2010 17:37
#9
Stefan Naglis wrote:
Looks like Chrysotus sp.


Thanks for the suggestion Stefan. I've looked at the genus ID criteria for Chrysotus, one part seems to fit which is the pale halters.

40. Stylus apical or subapical; halters usually light, white or yellow ... Chrysotus


The next step in the key however mentions also for Chrysotus:

41. Postpedicel higher than long; postpedicel not triangular; stylus more or less apical ... Chrysotus


The postpedicel on this fly doesn't look to be higher than long to me, but do the two need to be taken together or can they be taken separately?

I was wondering if this could be another Syntormon, there could be a thumb-like pedicel. I have pics of one from 2009 but a week earlier which is more green, from a dorsal view it looks similar and the wings seem to be the same (not sure about the diverging M vein) it appears to have a thumb-like pedicel but the legs are paler.

However, without checking the wings for which defines Rhaphium, I decided on that originally because of the body being a "metallic bronze green" I need to check the wing detail, OK, R4+5 does not look to be divergent, M1+2 does not diverge but there is a kink in it further up so I'm not sure if that is for vein towards the wing tip. I guess it means it is divergent so ruling out Rhapium, and I can't see if there's an A2. The frons colour probably also rules out Rhaphium.

Does anyone else have any thoughts? I will post the other fly from last year separately, they are better pics.

Posted by blowave on 28-12-2010 20:39
#10
I think I agree with Chrysotus sp. after looking long and hard! ;)

Thanks again Stefan.