STUDIES ON THE HOUSEFLY (MUSCA DOMESTICA L.): I. THE BIOLOGY AND LARGE SCALE PRODUCTION OF LABORATORY POPULATIONS
Using the Peet-Grady method for propagating houseflies required as biological test animals, variations were observed that had considerable bearing on production and subsequent adult life. Differences in length of life, fecundity, time of emergence of the adults from puparia, and the onset of egg laying occurred between different populations of flies. Investigations were carried out to determine the extent and causes of the variations and to develop more suitable techniques for producing large numbers on a more accurately predictable basis. Variability in production of puparia was found to be due largely to the age of female stock and rate of fermentation in the rearing medium through their effects on egg hatchability and larval survival and excessive crowding caused by high temperatures. By using eggs from genetically-selected stock of known age and rearing in a temperature-controlled medium, production of flies was increased and maintained at a constantly uniform rate. A description is given of the equipment and methods used.