Hepler James R, Athey Kacie, Enicks David, Abram Paul K, Gariepy Tara D, Talamas Elijah J, Beers Elizabeth
Tree Fruit Research and Extension Center, Washington State University, 1100 N Western Avenue, Wenatchee, WA 98801, USA.
Crop Sciences, University of Illinois at Urbana Champaign, 1101 W Peabody Drive, Urbana, IL 61801, USA.
Insects. 2020 Nov 23;11(11):822. doi: 10.3390/insects11110822.
Hidden trophic interactions are important in understanding food web ecology and evaluating the ecological risks and benefits associated with the introduction of exotic natural enemies in classical biological control programs. Although non-target risk is typically evaluated based on evidence of successful parasitism, parasitoid-induced host mortality not resulting in visible evidence of parasitism (i.e., nonreproductive effects) is often overlooked. The adventive establishment of , an exotic parasitoid of the introduced stink bug , provides an opportunity to investigate the total impact of this parasitoid on target and non-target hosts in the field. We developed a new methodology to measure nonreproductive effects in this system, involving a species-specific diagnostic PCR assay for . We applied this methodology to field-deployed eggs of four pentatomid species, coupled with traditional rearing techniques. Nonreproductive effects were responsible for the mortality of an additional 5.6% of eggs due to and were even more substantial in some of the non-target species (5.4-43.2%). The observed hidden mortality of native non-target species from an introduced parasitoid could change predictions about direct and indirect ecological interactions and the efficacy of biological control of the target pest.
隐藏的营养相互作用对于理解食物网生态学以及评估经典生物防治计划中引入外来天敌所带来的生态风险和益处至关重要。尽管非靶标风险通常是基于成功寄生的证据来评估的，但寄生蜂诱导的宿主死亡而未产生明显寄生证据（即非繁殖效应）的情况却常常被忽视。外来寄生蜂——引入的椿象的一种外来寄生蜂——的定殖，为研究该寄生蜂在田间对靶标和非靶标宿主的总体影响提供了一个机会。我们开发了一种新方法来测量该系统中的非繁殖效应，该方法涉及针对的物种特异性诊断PCR检测。我们将此方法应用于四种蝽象物种在田间部署的卵，并结合传统饲养技术。非繁殖效应导致另外5.6%的卵因死亡，在一些非靶标物种中甚至更为显著（5.4 - 43.2%）。观察到的外来寄生蜂对本地非靶标物种造成的隐藏死亡可能会改变对直接和间接生态相互作用以及靶标害虫生物防治效果的预测。
