The mating system of the flower bug Orius laevigatus

Many studies have examined the reproductive output of Orius species, predaceous biological control agents of several important agricultural pests. Little is known, however, about their mating system. We therefore studied the mating system of Orius laevigatus and examined the implications of intersexual interactions for the reproduction of this species. Virgin females were never found to lay eggs and copulations shorter than 105 s did not induce egg deposition. Female were found to be monandrous; mated females avoided any additional mating, 1, 7, and 14 days after the first mating. Females deposited significantly fewer eggs in the presence of five virgin males than in their absence. Male copulation and insemination abilities were tested when a virgin male was allowed to copulate sequentially with three virgin females in 1 day or with 1- or 2-day intervals between matings. Results indicated the males to be polygamous: they successfully inseminated all the offered females. Yet the total number of eggs laid by the first female to mate was significantly higher than the number laid by subsequent females. Time elapsed between matings had no significant effect on the reproductive output of the males. Implications of these results for mass rearing and field release of Orius laevigatus are discussed.