Posted by John Carr on 24-07-2011 14:39
#1
I saw this fly in a small patch of broadleaf vegetation in a wet spot on the alpine tundra of Mount Washington, New Hampshire, USA.
I think it is
Gymnopternus. The apparent bend in M in some pictures appears to be an illusion caused by a fold in the wing.
(Click for larger or view on
Flickr)
Edited by John Carr on 25-08-2011 01:33
Posted by John Carr on 04-12-2011 01:53
#3
This should be
Gymnopterus scotias Loew or
G. nigricoxa Van Duzee, two of the few species with black femora.
The last shot appears to show the hairs on the third segment of the antennae of
scotias. The key by Robinson (1964) rules out that species because there is a row of four dorsal bristles on the hind tibia. Using his key I would arrive at
G. robustus Van Duzee, which has a yellow hind basitarsus, or
G. nigricoxa. Thast last species is bluish and the mid tibia should have "five large bristles above". I count four including the apical bristle.
