9521821 MOORE Our research asks whether females discriminate among males on the basis of the male's ability to withstand stresses during development. This ability is reflected in the degree of fluctuating asymmetry in characters that have bilateral expression. We will use a combination of experimental manipulations, genetic experiments, and correlation studies of the cockroach, Nauphoeta cinera, to address several issues: 1) is female choice of mates or male-male competition influenced by the degree of asymmetry; 2) is the ability to reduce asymmetry genetically determined; and 3) do environment and degree of inbreeding influence the importance of fluctuating asymmetry? This research will provide information that will help minimize the mating disadvantages of individuals reared in biological control and endangered species programs. These programs rely on establishing breeding populations of target species. To be successful we must know how individuals from controlled breeding programs fare in competition for mates in a natural habitat. Many of the practices use to rear insects for release in these programs, such as inbreeding, result in increased fluctuating asymmetry. Our research will provide information on how mating patterns are affected by female discrimination against the degree of asymmetry.