The role of medium conditioning in the population dynamics of the housefly

Summary The role of larval medium conditioning on the behavior of larvae and of ovipositing adults of the housefly,Musca domestica L., was investigated through behavioral preference tests. Larvae were strongly attracted to medium conditioned by themselves or other larvae, while adult females overwhelmingly oviposited in fresh medium. Medium conditioning occurs within a few hours after hatching of an egg cohort and is effective in preventing overcrowding of a single site by shutting off further oviposition within 24 hours after eggs are initially deposited. A model of medium conditioning optimizes density for developing larvae and could also provide for regulation of local larval populations. This study was carried out during the tenure of grants from the National Science Foundation (GB-35473) and The National Institutes of Health (1-R01-AI-10988-01) to the senior author.