These studies were conducted in a variety of croplands and lawns. Soil samples were washed to recover gnat pupae and puparia; also, emergence cages were set in numerous date gardens and citrus groves, and the emerging gnats segregated to Hippelates species. Both procedures proved economical, rapid, and foolproof for determining the breeding niches of Hippelates gnats. Citrus groves, date gardens, vineyards, walnut groves, peach and apricot orchards, vegetable and field crop fields, golf courses, and lawns all bred Hippelates gnats to some degree. In the Coachella Valley of southern California, H. collusor (Townsend) outnumbered other gnat species in a majority of the breeding niches; H. hermsi Sabrosky was recovered in large numbers also. H. dorsalis Loew, H. pusio Loew, and H. robertsoni Sabrosky, occurred in low numbers in this valley. The type of crop had no direct relationship to the degree and extent of Hippelates breeding. Other numerous and uncontrollable factors such as frequency of irrigation, soil tillage, weed and covercrop growth, and type of soil do influence gnat breeding.