Privies as a Source of Fly Production in an Urban Area
H. F. Schoof AND
R. E. Siverly
Communicable Disease Center, Public Health Service, Atlanta, Ga., and Phoenix, Ariz.
1. Surveys of human excrement in privies at Phoenix, Arizona,during 195152 demonstrated that Musca domestica breedsreadily in this medium. Of 193 privies positive for fly breeding,44.6 per cent were infested with house fly larvae. Larvae ofSarcophaga, Muscina, and Hermetia occurred in 31.1, 16.1 and10.9 per cent of the positive samples, respectively.
2. Samplesof human excrement from chemically treated priviesin an urbanarea showed infestation rates of 31.9 per cent forM. domesticaand 20.7 per cent for Muscina spp. whereas thosefrom priviesin an untreated zone displayed rates of 3.6 percent and 59.0per cent for M. domestica and Muscina respectively.No conclusivedata explain this reversal in species predominancebut severalpossible causes are discussed.