Organic Wastes and Soil Additives as Producers ofHippelatesEye Gnats (Diptera-Chloropidae)

Abstract

Hippelates eye gnats breed heavily in damp, sandy soils where plant and animal materials arc incorporated during tillage, disturbance, or renovating of the breeding sources. In laboratory studies, various plant material such as Bermuda grass tops, carrot tops, cornstalk stubble, sugarbeet plant leaves, broccoli leaves, and onion tops incorporated into soil medium supported eye gnat development and emergence. Bermuda grass tops and corn stubble produced the fewest eye gnats, and the leafy plant tops produced greater numbers. Steer manure, chicken manure, and blood meal also yielded large numbers of eye gnats, but nitrohumus supported no eye gnat development to the emerging stage. In field studies, steer manure, chicken manure, and alfalfa hay produced substantial numbers of eye gnats. Extent of production was directly proportional to the concentration of steer and chicken manures. Nitrohumus and a chemical fertilizer (ammonium sulfate) sustained little or no eye gnat development and emergence. These two materials can be used as soil amendments without breeding pestiferous eye gnats.