Genetic link between mobility and sexual attractiveness in male Tribolium castaneum beetles

Securing females is a crucial determinant of male fitness in many species. Mate-searching efficiency is often associated with increased mobility in males, but an increased investment in movement may reduce other fitness traits via potential trade-offs. In precopulatory sexual selection via female mate choice, the rate of encounter with females and the attractiveness of males are essential to increase male mating success. If there is a trade-off between mobility and attractiveness in males, males with higher mobility may show lower attractiveness. We here assessed whether artificial selection of mobility affected male attractiveness in the red flour beetle, Tribolium castaneum. We compared the olfactory attractiveness of males (due to 4,8-dimethyldecanal) between strains having genetically higher mobility or lower mobility. The results indicated that females were significantly more attracted to the odours of lower mobility males. Therefore, our results suggested that a genetic trade-off might have occurred between mobility and attractiveness in males. This cost–benefit balance may lead to the maintenance of individual differences in mobility within a population.