Thread subject: Diptera.info :: Beach fly 2013-VIII-18 (= Proctacanthus coquillettii)

Posted by John Carr on 06-09-2013 13:29
#1

On a beach in California, USA near the Mexican border. August 18, 2013.

Edited by John Carr on 07-09-2013 00:18

Posted by Eric Fisher on 07-09-2013 00:05
#2

Proctacanthus coquillettii, male. Nice shot of this sand dune-loving fly limited to the southern part of the Colorado River drainage.

Posted by John Carr on 07-09-2013 00:18
#3

Thanks. Is beard color sexually dimorphic? I also saw a robber fly with white beard.

Posted by Eric Fisher on 13-09-2013 08:19
#4

Yes, the female has a white beard and the body is paler in color (being gray, with the apex of the large ovipositor shiny black). The wings of the male have a large brown spot that covers most of the middle third of the wing, while the female has nearly entirely clear wing, with just a faint brown shadow in the middle third.

Some males of Proctacanthus coquillettii have whitish beards. The intensity of the yellowish-orange color hairs in your male fly seems unusual, and most males have these hairs a much paler yellow color or even white.