Sexually selected characters are thought to be costly to develop and maintain. Purely Fisherian models of sexual selection predict that if males do not vary in their investment in sexual traits relative to their ability to bear the costs of producing or maintaining these traits, there should be a negative relationship between male longevity or survival and trait expression. Alternatively, genetic viability models predict that males with more elaborated sexual traits are more likely to be in better condition and as such, variation in condition would reflect underlying differences in male genetic quality. The research presented here demonstrates empirical evidence for the genetic basis of condition-dependent sexually selected male characters in the ultrasonic pyrallid moth, Achroia grisella. By constructing a genetic variance/covariance matrix (G-matrix) of overall attractiveness, attractiveness components, and life history traits through a quantitative genetic breeding experiment, a positive genetic correlation was determined between attractiveness and body weight (a measure of condition), attractiveness and adult lifespan, and attractiveness and nightly calling activity. Consequently, larger males are not only more attractive but also have more opportunity to mate because they live longer and spend more time nightly in the sexual selection arena. These results contradict the dogmatic expectations of Fisherian models of sexual selection while supporting those for condition-dependent models of male attractiveness.
Species 1: Lepidoptera Pyrallidae Achroia grisella (lesser wax moth)
Keywords: Sexual selection, Behavioral genetics
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA