Female Foundresses Egg Parasitoids Deprived of Host: Do Age and Mating Status Affect Reproductive Attributes of Three Egg Parasitoids (Hymenoptera: Scelionidae)?

Egg parasitoids forage for hosts in a dynamic ecosystem. The short longevity of the adult stage forces them to access a host in a short time. The current study examined optimal reproductive attributes of three egg parasitoids: Trissolcus agriope (Kozlov and Le), Trissolcus delucchii Kozlov and Trissolcus niceppe (Kozlov and Le) (Hymenoptera: Scelionidae). The characteristics used were fecundity, immature survival rate, daily reproduction, and sex ratio that emerged from host eggs, Acrosternum arabicum Wagner (Hemipteran: Pentatomidae). Experiments were conducted separately in the first day of emergence, 20, 40, 60 and 80% of the mean longevity of naïve foundresses, influenced by mating status and under host deprivation conditions. The results revealed that the immature survival rate of foundresses of T. agriope on the first day of emergence, and at 20 and 40% of longevity were higher than other progeny produced by the three parasitoids, whether mated or unmated. All foundresses produced maximum progeny in the first oviposition experience, although the oviposition period was continuous. Regardless of mating status, the progeny production of T. agriope and T. niceppe declined in the last two stages (60 and 80% of female longevity). The proportion of male progeny increased with foundress age from 40% of their longevity. The species-specific performance of female parasitoids is discussed with regards to oogenesis, oosorption and survival of male gametes in female spermatheca. The results provided information about suitable female age for mass rearing and mass release programs, whether in inundation method or for determination of inoculation rhythms.