Subfamily Stenopogoninae

Genera found in Wyoming: Backomyia, Callinicus, Ospriocerus, Scleropogon, and Stenopogon .

Key to Genera [adapted from Wood (1981)]

1 Head very narrow, as high as wide, appearing more less circular in frontal view.................................... 2

- Head wider than high.................................................................................. 4

2 Katatergite without setae or bristles............................................................... Stenopogon

- Katatergite with setae, bristles or both..................................................................... 3

3 Antennal scape 1–1.5 times length of pedicel; second and third flagellomeres forming an apically pointed stylus with a short spine at apex; wings usually hyaline.............................................................. Scleropogon

- Scape 2 times or more as long as pedicel; second and third flagellomeres absent, or if present, truncate at apex with spine arising from pit; wings usually brown.................................................................. Ospriocerus

4 Mid-tibiae with a pair of moderately strong ventral bristles at apex directed proximally at a 60–90° angle........ Callinicus

- Mid-tibiae with bristles directed distally........................................................... Backomyia