Diptera.info

Posted by Stephen on 13-10-2006 14:00

Genus Tipulogaster? When I first saw this fly at a distance, I thought it was a wasp. Seeing it through the viewfinder, though, I recognized it as a small robber fly. Have I got the genus right?

Female, judging by the plump abdomen?

Length, 4.2 mm. Photographed flying slowly through the weeds along a very small stream. Meadow and woodland nearby. West Virginia USA. Photographed 1 October 2006.

Posted by Paul Beuk on 13-10-2006 14:40

In Europe this would be Leptogaster. I do not know whether there are related genera in the Nearctic.

Posted by Stephen on 13-10-2006 15:08

Bugguide.net has three genera listed for subfamily Leptogastrinae in the Nearctic: Leptogaster, Tipulogaster, and Psilonyx. Most of the BugGuide images are Tipulogaster, which my image seems to match. But there is only one Leptogaster image on the site to compare to. No info on BugGuide about how to separate Leptogaster from Tipulogaster, unfortunately.

Posted by Dmitry Gavryushin on 13-10-2006 16:03

Stephen, you coul try Geller-Grimm & Artigas's key for Leptogastrinae (http://www.geller...rinae.html), especially if you have more pictures, including the head close-ups. As far as i can see the difference between Leptogaster and Tipulogaster is in the length of flagellum compared with the combined length of scape and pedicel; you should exclude other genera, though (there's more than 3 of them...)

Edited by Dmitry Gavryushin on 13-10-2006 16:03

Posted by Stephen on 16-10-2006 11:32

Thank-you Black for that link! I will work with it soon, though unfortunately I don't have any good photos of the head except in lateral view.

I see I uploaded only one of the two pictures, so here is the other one. The fly flew everytime I took a photo, and I only got two got photos before I lost her in the weeds.