Most insects can mate multiple times. With the increasing of male mating frequency, male parasitoid wasps would have less sperm, and the female partners would gain less sperm during copulation, which will make them lay more unfertilized eggs, developing into male offspring. Some solitary female parasitoid wasps can only mate once in the life span.In this article, the mating behavior of the solitary endoparasitoid, Pachycrepoideus vindemmiae Rondani, was described, with the pupae of houseflies as the hosts, and the effects of male mating frequency on the production of the female partners and the possible mating times of the mated females were studied. The results showed that the mating behavior of P.