Rossbacher Silvan, Vorburger Christoph
Aquatic Ecology Eawag Dübendorf Switzerland.
Institute of Integrative Biology ETH Zürich Zürich Switzerland.
Evol Appl. 2020 Mar 6;13(8):1868-1876. doi: 10.1111/eva.12934. eCollection 2020 Sep.
There is increasing demand for sustainable pest management to reduce harmful effects of pesticides on the environment and human health. For pest aphids, biological control with parasitoid wasps provides a welcome alternative, particularly in greenhouses. However, aphids are frequently infected with the heritable bacterial endosymbiont , which increases resistance to parasitoids and thereby hampers biological control. Using the black bean aphid () and its main parasitoid , we tested whether prior adaptation of parasitoids can improve the control of symbiont-protected pests. We had parasitoid lines adapted to two different strains of by experimental evolution, as well as parasitoids evolved on -free aphids. We compared their ability to control caged aphid populations comprising 60% unprotected and 40% -protected aphids, with both strains present in the populations. Parasitoids that were not adapted to had virtually no effect on aphid population dynamics compared to parasitoid-free controls, but one of the adapted lines and a mixture of both adapted lines controlled aphids successfully, strongly benefitting plant growth. Selection by parasitoids altered aphid population composition in a very specific manner. Aphid populations became dominated by -protected aphids in the presence of parasitoids, and each adapted parasitoid line selected for the strain it was not adapted to. This study shows, for the first time, that prior adaptation of parasitoids improves biological control of symbiont-protected pests, but the high specificity of parasitoid counter-resistance may represent a challenge for its implementation.
对可持续害虫管理的需求日益增加，以减少农药对环境和人类健康的有害影响。对于害虫蚜虫，利用寄生蜂进行生物防治提供了一种受欢迎的替代方法，特别是在温室中。然而，蚜虫经常感染可遗传的细菌内共生体，这会增加对寄生蜂的抗性，从而阻碍生物防治。我们以黑豆蚜（）及其主要寄生蜂为研究对象，测试了寄生蜂的预先适应性是否能改善对受共生体保护害虫的控制。我们通过实验进化使寄生蜂品系适应两种不同的菌株，以及在无菌株的蚜虫上进化出的寄生蜂。我们比较了它们控制笼养蚜虫种群的能力，该种群由60%未受保护和40%受保护的蚜虫组成，两种菌株都存在于种群中。与无寄生蜂的对照组相比，未适应菌株的寄生蜂对蚜虫种群动态几乎没有影响，但其中一个适应品系和两个适应品系的混合物成功地控制了蚜虫，对植物生长有很大益处。寄生蜂的选择以一种非常特殊的方式改变了蚜虫种群组成。在有寄生蜂的情况下，蚜虫种群由受保护的蚜虫主导，并且每个适应的寄生蜂品系选择了它未适应的菌株。这项研究首次表明，寄生蜂的预先适应性提高了对受共生体保护害虫的生物防治效果，但寄生蜂反抗性的高特异性可能对其实施构成挑战。
