Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau of Ministry of Agriculture, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
Hubei Tobacco Company Enshi State Co., Ltd., Enshi, Hubei, China.
Insect Sci. 2020 Oct;27(5):1101-1110. doi: 10.1111/1744-7917.12724. Epub 2019 Oct 15.
Intraguild predation (IGP) has been commonly reported between predators and parasitoids used as biological control agents as predators consuming parasitoids within their hosts. However, the effect of parasitoid-mummy consumption on the fitness of the predator and subsequent oviposition site selection have not been well studied. In our study, we conducted two laboratory experiments to examine the influence of Aphidius gifuensis Ashmead (Hymenoptera: Braconidae) mummies as prey on fitness and subsequently oviposition site selection of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Results indicate that when H. axyridis was reared on A. gifuensis mummies only, its larval development was prolonged, and body weight of the 4th instar larvae and newly emerged adults, and fecundity decreased. Moreover, H. axyridis did not exhibit oviposition preference on plants infested with unparasitized aphids or aphids parasitized for shorter than 9 days. However, compared with plants with mummies (parasitized ≥9 days), H. axyridis laid more eggs on plants with unparasitized aphids. In contrast, H. axyridis previously fed with A. gifuensis mummies did not show a significant oviposition preference between plants with unparasitized aphids and those with mummies (parasitized ≥9 days). Overall, our results suggest that mummy consumption reduced the fitness of H. axyridis. Although H. axyridis avoided laying eggs on plants with A. gifuensis mummies, prior feeding experience on A. gifuensis mummies could alter the oviposition site preference. Thus, in biological control practice, prior feeding experience of H. axyridis should be carefully considered for reduction of IGP and increase of fitness of H. axyridis on A. gifuensis.
种内捕食（IGP）在作为生物防治剂的捕食者和寄生蜂之间很常见，因为捕食者会在其宿主内捕食寄生蜂。然而，寄生蜂蛹被消耗对捕食者的适合度及其随后的产卵地点选择的影响尚未得到很好的研究。在我们的研究中，我们进行了两项实验室实验，以研究 Aphis gifuensis Ashmead（膜翅目：Braconidae）作为猎物的蜂蛹对 Harmonia axyridis（Pallas）（鞘翅目：Coccinellidae）的适合度和随后的产卵地点选择的影响。结果表明，当 H. axyridis 仅以 A. gifuensis 蜂蛹为食时，其幼虫发育延长，4 龄幼虫和新羽化成虫的体重以及产卵量均降低。此外，H. axyridis 对未被寄生的蚜虫或寄生时间少于 9 天的蚜虫的植物没有产卵偏好。然而，与有蜂蛹（寄生时间≥9 天）的植物相比，H. axyridis 在没有被寄生的蚜虫的植物上产卵更多。相比之下，先前以 A. gifuensis 蜂蛹为食的 H. axyridis 在未被寄生的蚜虫和有蜂蛹（寄生时间≥9 天）的植物之间没有表现出显著的产卵偏好。总体而言，我们的研究结果表明，蜂蛹的消耗降低了 H. axyridis 的适合度。尽管 H. axyridis 避免在有 A. gifuensis 蜂蛹的植物上产卵，但先前对 A. gifuensis 蜂蛹的取食经验可能会改变其产卵地点的偏好。因此，在生物防治实践中，应仔细考虑 H. axyridis 先前的取食经验，以减少 IGP 并提高其在 A. gifuensis 上的适合度。
