Temporally fluctuating selection of sex-limited signaling traits in the Texas field cricket, Gryllus texensis.

Gryllus texensis males produce acoustic mating signals and display extensive heritable variation in when and how much time they spend signaling throughout the night. The goal of this research is to elucidate the potential mechanism responsible for maintaining this heritable variation. Mating signals attract female crickets. In low-density spring populations females select males that signal most often; in high-density fall populations mating appears random with respect to signaling time. Mating signals also inadvertently attract acoustically orienting parasitoid flies; parasitoids are prevalent during the first half of the evening in the fall mating season. I hypothesized that mating signals are influenced by sex-limited temporally fluctuating selection. I predicted how mating signals would respond to this pattern of cyclical selection a priori, and then measured the sexual characters over four successive generations. I provide correlative evidence that mating signals appear to respond to sex-limited temporally fluctuating selection. These results indicate that sex-limited temporally fluctuating selection may play a role in the maintenance of variation in these sexual characters.