Department of Agricultural, Food and Forest Sciences, University of Palermo Viale delle Scienze, Palermo, Italy.
Interuniversity Center for Studies on Bioinspired Agro-Environmental Technology (BAT Center), University of Napoli Federico II, Portici, Italy.
Pest Manag Sci. 2022 Aug;78(8):3376-3383. doi: 10.1002/ps.6965. Epub 2022 May 26.
Interspecific competition in insect parasitoids is an important ecological phenomenon that has relevant implications for biological pest control. To date, interspecific intrinsic (=larval) competition has been intensively studied, while investigations on extrinsic (=adult) competition have often lagged behind. In this study we examined the role played by parasitoid reproductive traits and host clutch size on the outcome of extrinsic competition between Trissolcus basalis (Wollaston) and Ooencyrtus telenomicida (Vassiliev), two egg parasitoids of the pest Nezara viridula (L). Laboratory experiments were conducted by allowing both parasitoid species to exploit an egg mass made of 10, 20, 30, or 40 hosts through single or simultaneous releases. Furthermore, under field conditions, egg masses consisting of 10 or 40 hosts were exposed in a tomato crop in order to validate laboratory investigation.
The results show that the egg mass size is an important predictor of extrinsic competition in our study system as a higher proportion of T. basalis emerged from large egg masses, while O. telenomicida dominated in small egg masses. Analysis of reproductive traits of parasitoid species indicates that T. basalis has superior abilities in host exploitation compared with O. telenomicida.
We found that contrasting reproductive traits of two competing egg parasitoid species facilitate coexistence on a shared stink bug host. This work also highlights the importance to consider extrinsic competitive interactions between parasitoid species in a biological control perspective. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
昆虫寄生蜂之间的种间竞争是一种重要的生态现象，对生物防治具有重要意义。迄今为止，种内（幼虫期）竞争已得到深入研究，而种间（成虫期）竞争的研究往往滞后。本研究考察了寄生蜂繁殖特征和寄主卵团大小对小菜蛾卵寄生蜂微红皱茧蜂和广赤眼蜂种间竞争结果的影响。通过单独或同时释放 10、20、30 或 40 个寄主卵的方式，在实验室中进行了实验。此外，在田间条件下，将由 10 或 40 个寄主组成的卵团暴露在番茄作物中，以验证实验室的调查结果。
结果表明，卵团大小是本研究系统中种间竞争的一个重要预测因子，因为较大的卵团中出现了更多的微红皱茧蜂，而广赤眼蜂则在较小的卵团中占优势。对寄生蜂物种繁殖特征的分析表明，与广赤眼蜂相比，微红皱茧蜂具有优越的寄主利用能力。
我们发现，两种竞争的卵寄生蜂具有不同的繁殖特征，这有助于它们在共享的臭蝽寄主上共存。这项工作还强调了在生物防治的角度上考虑寄生蜂种间的种间竞争相互作用的重要性。© 2022 作者。Pest Management Science 由 John Wiley & Sons Ltd 代表化学工业协会出版。
