Sterile-male method of population control.

The principle of animal population control through the use of sexually sterile males has been demonstrated for insects. Sexually sterile males that retain their sexual vigor and behavior will exert greater influence in regulating animal populations than can be achieved by destroying or removing the same number of individuals from the population. This hypothesis is supported by calculations showing theoretical population trends in assumed insect and animal populations subjected to treatments that destroy or eliminate certain percentages of the individuals as compared with a procedure that retains or replaces the same number of males in the population after sterilization. The maximum regulating effect that can be achieved is in direct proportion to the ratio of sterile to fertile males competing for mates. The advantages of inducing sexual sterility in a natural population of an insect species by chemical or other treatment over the method of rearing and releasing a dominating population of sterile males are considered. It is suggested that the sterile-male method may have practical application for undesirable populations of certain wild animals as well as for insects.