Differences in Attack Avoidance and Mating Success between Strains Artificially Selected for Dispersal Distance in <i>Tribolium castaneum</i>

<div><p>Individuals of both dispersal and non-dispersal types (disperser and non-disperser) are found in a population, suggesting that each type has both costs and benefits for fitness. However, few studies have examined the trade-off between the costs and benefits for the types. Here, we artificially selected for walking distance, i.e., an indicator of dispersal ability, in the red flour beetle <i>Tribolium castaneum</i> and established strains with longer (L-strains) or shorter (S-strains) walking distances. We then compared the frequency of predation by the assassin bug <i>Amphibolus venator</i> and the mating frequency of the selected strains. L-strain beetles suffered higher predation risk, than did S-strain beetles. L-strain males had significantly increased mating success compared to S-strain males, but females did not show a significant difference between the strains. The current results showed the existence of a trade-off between predation avoidance and mating success associated with dispersal types at a genetic level only in males. This finding can help to explain the maintenance of variation in dispersal ability within a population.</p>