Population models on the release of chemosterilants for pest control.
Models are presented for determining the feasibility of population control by releasing sterilants and pesticides, singly or in combination, into the environment. Only the effects on the population equilibria were determined. It is shown that for a single species with a simple life-cycle, the release of sterilants or pesticides would reduce population size singly or in combination. For a single species with a 2-stage life-cycle, the release of sterilants or pesticides would usually reduce numbers, but their effects could be antagonistic. A pest species in competition with another species would usually decrease in response to sterilant or pesticide releases unless the competitor species was numerically quite dominant and competed strongly with the pest. A pest species limited mainly by predation would usually increase with sterilant or pesticide releases unless the predators were strongly crowded. A pest species limited by both predation and competition would be unlikely to decrease with the release of pesticides or sterilants if its birth rate were lower than that of the competitors or if the competitors exerted little depressing effect on the pest.