School of Life Sciences, Anhui Key Laboratory of Biodiversity Research and Ecological Protection in Southwest Anhui Province, Anqing Normal University, Anqing 246133, China.
School of Agriculture and Environment, Massey University, Palmerston North 11222, New Zealand.
J Insect Sci. 2024 Jan 1;24(1). doi: 10.1093/jisesa/ieae016.
Females of host-feeding parasitic wasps often partition hosts of different stages for feeding and parasitization, but the underlying behavioral mechanisms are largely unknown, making it difficult to evaluate parasitoid-host interactions and their effects on biological control success. Tamarixia triozae (Burks) is an ectoparasitoid of tomato-potato psyllid Bactericera cockerelli (Šulc), which utilizes nymphs and kills them both by parasitization and host feeding. In this study, we exposed female wasps to 1st- to 5th-instar psyllid nymphs simultaneously and made 13-h continuous video recording of parasitoid-host interactions. We then quantified host stage-dependent handling time for feeding and oviposition and behaviors of parasitoid attacks and host defenses from encountering to successful feeding and oviposition. Female wasps were more likely to encounter and evaluate older hosts. However, the encounter and evaluation did not necessarily result in the success of feeding and oviposition. Our findings suggest that (i) T. triozae continues to assess the host using its ovipositor after the evaluation phase, (ii) females prefer the mid-aged hosts for feeding piercing and feeding and the later instars for oviposition probing and oviposition, (iii) the combination of stage-specific host nutrition value, integument thickness and defense behavior determines the success of feeding attacks, and (iv) the optimal host resource for parasitoid offspring fitness defines host stage selection for oviposition. This study contributes to our understanding of parasitoid-host interactions and mechanisms behind host stage selections.
雌性寄生蜂通常会将不同龄期的宿主分开取食和寄生，但背后的行为机制在很大程度上尚不清楚，这使得评估寄生蜂-宿主相互作用及其对生物防治成功的影响变得困难。番茄烟粉虱啮小蜂（Tamarixia triozae）是番茄烟粉虱（Bactericera cockerelli）的外寄生蜂，它利用若虫，并通过寄生和宿主取食来杀死它们。在这项研究中，我们同时向雌性寄生蜂暴露 1-5 龄的烟粉虱若虫，并对寄生蜂-宿主相互作用进行了 13 小时的连续视频记录。然后，我们量化了宿主龄期依赖性的取食和产卵处理时间，以及从遭遇到成功取食和产卵的寄生蜂攻击和宿主防御行为。雌性寄生蜂更有可能遇到和评估年龄较大的宿主。然而，遭遇和评估并不一定会导致取食和产卵的成功。我们的研究结果表明：（i）T. triozae 在评估阶段后继续使用其产卵器来评估宿主；（ii）雌性寄生蜂更喜欢取食中期龄期的宿主进行刺穿和取食，而更喜欢后期龄期的宿主进行产卵探测和产卵；（iii）宿主营养值、体壁厚度和防御行为的特定龄期组合决定了取食攻击的成功，以及（iv）最适合寄生蜂后代生存的宿主资源决定了产卵时对宿主龄期的选择。这项研究有助于我们理解寄生蜂-宿主相互作用和宿主龄期选择的背后机制。
