Genus Gymnoprosopa Townsend, 1892

Gymnoprosopa Townsend, 1892: 108 .

Type species: Gymnoprosopa polita Townsend, 1892 ; by original designation.

Gymnoprosopa : Allen, 1926: 95 [revision]; Downes, 1965: 936 [catalogue]; Krombein and Kurczewski, 1963: 139 [habits]; Shewell, 1987: 1182 [in key]; Spofford et al., 1989: 255 [habits]; Pape, 1996: 89 [catalogue].

Bright colored small flies (3.5–6.0 mm in length). Frontal vitta matt yellow to reddish, as wide or widened as one as parafrontalia; fr not reaching below antennal base, almost not divergent; orb 1+2; genae covered by inconspicuous black hairs, without pale setae; lower margin of head almost not shortened; lunule bare. r 5 open; abdominal tergites with distinct black bands at hind surfaces of tergites; sexual dimorphism practically absent. Six species are distributed in the Nearctic region.

Habits: The larvae of Gymnoprosopa sp. were developed at paralyzed nymphs and adults of Tridactylus sp. ( Orthoptera ) in nests of sphecoid wasp Tachytes mergus (Krombein and Kurczewski, 1963; Spofford et al., 1989).