Eye Gnat

Liohippelates pusio (family Chloropidae) is a minute, shiny black fly measuring only 1.5-2.5 mm, with yellowish to tan legs and clear wings held flat over the abdomen. Females deposit eggs singly or in small clusters in loose, sandy, organically enriched soil, particularly freshly cultivated ground. Larvae are small, cream-colored maggots that feed on decaying organic matter and soil microorganisms, completing three instars in 7-11 days. Pupation occurs in the top few centimeters of soil, and the total egg-to-adult cycle can be completed in as little as 12-21 days at 27-30°C, producing overlapping generations throughout the warm season.

Eye gnats are non-biting but persistently attracted to mucous secretions of the eyes, nose, and mouth, as well as to sebum, sweat, blood, and pus from open wounds. They hover and repeatedly land on the face and exposed skin, using sponging mouthparts equipped with rasping spines that can abrade tissue. This behavior makes them efficient mechanical vectors of bacterial conjunctivitis (pinkeye), acute hemorrhagic conjunctivitis, bovine mastitis pathogens, and yaws. They are day-active, most abundant in the hours after sunrise and before sunset, and generally disperse within a few hundred meters of larval habitat, though wind can carry them farther.