Reproductive biology of Trichopria anastrephae Lima (Hymenoptera: Diapriidae), a biological control agent of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae)

Abstract Hymenopteran parasitoids, like any other insect, employ strategies to ensure their reproduction. Here, we present mating strategies used by the pupal parasitoid Trichopria anastrephae Lima (Hymenoptera: Diapriidae), a potential biocontrol agent of the invasive pest species Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Adults from this species emerge in the first hours of photophase, and males emerge before females, demonstrating that T. anastrephae is a protandrous species. Parasitoid age when first mated influences the parasitism and sex ratio. Younger females result in a higher number of offspring, while older males result in a more female-biased sex ratio of offspring. Both males and females are polygamic, and the order in which a female is mated by the male affects parasitism, viability of parasitized pupae, and sex ratio of offspring, with the first female performing the highest parasitism and sex ratio, but the lowest viability. Females that are allowed to mate multiple times generate lower numbers of offspring when compared to virgin or single-mated females, but the highest sex ratio. Data present in this study can be used to improve parasitoid rearing and field releases of T. anastrephae, to be used in biological control programs for D. suzukii.