Posted by John Carr on 26-02-2015 02:44
#4
2+2 paired ad+pd on hind tibia and pale color suggest
Pegomya.
See if you can place it based on external characters using
Huckett, H. C. 1941 A Revision of the North American Species Belonging to the Genus Pegomyia (Diptera: Muscidae). Memoirs of the American Entomological Society 10.
and then check Griffiths' revision to confirm.