tiny flies are black or yellow in coloration and 1.5 to 2.5 mm long. The wings are short, broadly rounded at the tip and they are devoid of closed cells except close to the base (anal cell and subcostal vein are both absent). They have small mouths and short antennae each with a stout, bare hair. This pest may cause damage to bent grass greens on golf courses and occasionally to turf grasses. The small larvae tunnel into and feed on the grass stems near the soil surface. Plants that are infested generally wilt and die. The presence of this pest may be detected if large numbers of small black flies are observed over the grass surface from mid- to late morning.
All common lawn grasses are susceptible with bent grass being most preferred. Other plants that are more susceptible than the above are wheat, rye, timothy and corn. In some instances, pasture grasses are also a preferred host. They breed in decaying vegetation and excrement and feed on pus, blood, and other animal fluids. Because some frit flies are attracted to the eyes, they are also called eye gnats.