Department of Plant Protection, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
Department of Entomology, Kansas State University, Agricultural Research Center-Hays, Hays, KS, USA.
Environ Entomol. 2024 Oct 11;53(5):753-759. doi: 10.1093/ee/nvae071.
The stink bugs Acrosternum arabicum Wagner and Brachynema germari Kolenati (Hemiptera: Pentatomidae) damage developing pistachio nuts in Iran. Ooencyrtus egeria Huang and Noyes (Hymenoptera: Encyrtidae) parasitizes eggs of both species, alternating between them seasonally. We compared the biological and life history attributes of O. egeria reared for 3 generations on each host species with those that had been transferred to the alternate host for 2 generations. We also tested female responses to host egg density. Eggs of B. germari were parasitized at higher rates and yielded faster wasp development, heavier female progeny with greater fecundity, and a more female-biased sex ratio, than eggs of A. arabicum. Rearing on A. arabicum did not diminish wasp fitness on B. germari, and the F1 progeny of wasps switched to A. arabicum inherited some beneficial parental effects from rearing on B. germari. Regardless of host species, females parasitized fewer eggs in 8 h as density increased from 10 to 30 eggs, but progeny sex ratio (% female) increased. The anomalous response to host density appears to arise from a combination of behavioral and egg load constraints. Females mature only 10-12 eggs per day. Carefully inspect egg clusters before selecting the most suitable eggs for oviposition, a more time-consuming process for large clusters. Our results indicate that rearing O. egeria on eggs of A. arabicum, which are more convenient and cost-effective to produce than those of B. germari, will not diminish its performance on B. germari following augmentative release, beyond a slight reduction in female fecundity.
梨冠网蝽 Acrosternum arabicum Wagner 和 Brachynema germari Kolenati（半翅目：Pentatomidae）会损害伊朗正在发育的开心果。长尾跳小蜂 Ooencyrtus egeria Huang 和 Noyes（膜翅目：Encyrtidae）会寄生这两个物种的卵，并且会根据季节在它们之间交替寄生。我们比较了在每个宿主物种上连续培养 3 代的 O. egeria 和连续培养 2 代后转移到另一种宿主的 O. egeria 的生物学和生活史特征。我们还测试了雌性对宿主卵密度的反应。B. germari 的卵被寄生的比率更高，且蜂的发育速度更快，雌性后代的体重更重，繁殖力更强，雌性与雄性的比例也更偏向雌性。在 A. arabicum 上饲养不会降低 O. egeria 在 B. germari 上的适应性，并且转移到 A. arabicum 的第一代后代继承了一些来自 B. germari 饲养的有益的母体效应。无论宿主物种如何，随着卵密度从 10 个增加到 30 个，寄生的卵数量减少，但后代的性别比例（%雌性）增加。对宿主密度的异常反应似乎是由行为和卵负荷限制共同作用引起的。雌性每天只能成熟 10-12 个卵。在选择最适合产卵的卵之前，会仔细检查卵簇，对于较大的卵簇来说，这是一个更耗时的过程。我们的结果表明，在大量生产更方便且更具成本效益的 A. arabicum 卵的情况下，连续培养 O. egeria 不会降低其在 B. germari 上的性能，除了对雌性繁殖力略有降低之外。
