Effect of daily synchronization of sexual activity on mating success in laboratory populations of two species of Dacus (Diptera : Tephritidae)

Abstract

In crowded laboratory populations of D. tryoni and D. neohumeralis, males of both species locate mates by random attempts at copulation with nearby adults, regardless of sex. But a much greater percentage of attempts by D. tryoni males resulted in copulation. The daily period of mating of D. tryoni in crowded laboratory populations was restricted to 1 hr at dusk while mating in populations of D. neohumeralis extended over a 7-hr period, earlier in the day. If it is assumed that individuals of both species remain sexually active for a similar duration of time each day then both the higher frequency of mating and the greater percentage of successful attempts at copulation found among D. tryoni can be explained by the resulting synchronization in time of sexual activity.