Thread subject: Diptera.info :: What Family?

Posted by Stephen on 21-07-2006 13:09
#1

My first thought was Rhagionidae, with all those golden fine hairs on the thorax. But the wing venation doesn't seem right.

I'm posting three pictures, all of the same individual, photographed resting on a Poison Ivy leaf. The length from the front of the face to the rear of the wings was 5.9 mm.

Location: beside a woodland stream, West Virginia USA.

Date: 20 July 2006.

ID help appreciated!

Posted by Stephen on 21-07-2006 13:11
#2

Here's a second view.

Posted by Stephen on 21-07-2006 13:12
#3

Here is the third and final view.

Posted by Tony Irwin on 21-07-2006 13:14
#4

Hi Stephen
Pollenia (Calliphoridae) female. The combination of wavy golden hairs on the thorax, and this wing venation doesn't occur in any other genus.
(On this forum, I'm sure someone will point out if I'm wrong!) :D

Posted by Stephen on 21-07-2006 13:23
#5

Thanks, Tony! I photographed a Pollenia once before, but it had much sparser golden hairs (or maybe they had worn off) so I didn't think the two photographed specimens to be very similar. Now that I compare the two pictures, I do see the similarity. Both have a sort of black and grey checkerboard pattern on the abdomen, too.

Thanks so much for your ID and explanation!

Posted by Tony Irwin on 21-07-2006 14:08
#6

The golden hairs are deciduous. Freshly emerged Pollenia have a good covering, but they quickly become worn and late in the season, and especially after overwintering (they hibernate in caves, hollow trees and attic rooms) they can be quite bare. However careful examination of the sides of the thorax always reveal a few of the distictive hairs.