海氏桨角蚜小蜂响应短时高温的“寄生和取食” 行为抉择与能量权衡机制

Bemisia tabaci Q-biotype is one of the most serious invasive agricultural pests in China. As its strongly insecticide resistance and thermal tolerance, biological control is becoming the mainly management measure of this pest. In this proposed project, we will focus on the question that fluctuating high temperature could affect the behavior trade-off between oviposition and host feeding and physiological mechanism of synovigenic parasitoid. To better understand the behavior choices and physiological mechanisms of a host-feeding synovigenic whitefly parasitoid Eretmocerus hayati under fluctuating temperature, three experiments will be set up: firstly, the behavior trade-off between ovipsition and host feeding and the biological control efficiency of parasitoid will be evaluated when parasitoid is exposed to fluctuating temperature with different frequencies and severities at a single stage, such as larval, pupa or adult; Secondly, we further explore the behavior trade-off and bio-control efficiency of this parasitoid when two or three stages of parasitoid meet fluctuating temperature; thirdly, we analyze the energy use-structural allocation trade-off of parasitoids at pre-adult stage and nutrient allocation trade-off between capital resource and income resource at adult stage when fluctuating temperature is coming. This completion of this expecting project will improve a better understanding of the behavioral ecology and physiological responding mechanism of thermal adaptation of a synovigenic parasitoid. Our results will provide some new insights into overcoming the challenge of sustainable management of Bemisia tabaci.

应用耐高温的天敌防控耐高温的害虫是一种重要的生防措施。针对重大农业害虫Q型烟粉虱耐高温而难防治的问题，本项目以优势寄生蜂海氏桨角蚜小蜂耐高温种群为对象，重点针对其耐高温、寄主取食和卵育型（羽化后需要通过取食寄主以继续促进卵子发生）的特点，围绕短时高温影响雌蜂当前生殖（寄生）和未来生殖（取食）的行为抉择及其对应的能量分配策略的科学问题，采用实验生态学、行为生态学及昆虫生理学相结合的方法，首先研究不同发育阶段寄生蜂分别响应短时高温的取食和寄生的行为策略并进而其对控制潜力的影响；然后研究多个发育阶段寄生蜂同时遭遇短时高温对其行为抉择和生防潜力的“级联”效应；在此基础上，测定和分析短时高温对雌蜂成虫前期和成虫期的能量分配和利用策略。研究结果可以从理论上丰富卵育型寄生蜂在极端气候下的行为适应策略和能量分配规律，实践上有利于评估该类寄生蜂在短时高温下的控害潜力，为应用烟粉虱的生物防治策略提供指导。

烟粉虱是我国的重大农业入侵害虫之一，其不仅直接为害寄主植物，而且还能传播双生病毒造成间接危害。目前，该害虫的主要防治措施为化学防治，致使其抗药性越来越强，增加了防控难度。因此，迫切需要研发和拓宽针对烟粉虱的生物防治技术，达到绿色防控的目的。该项目选取烟粉虱的本地优势寄生蜂海氏桨角蚜小蜂为研究对象，系统评价了环境温度（尤其是短时高温）对寄生蜂寄生/取食行为抉择、生活史参数及种群生命表的影响，期望能够明确温度在该寄生蜂的种群消长过程中的生态学作用机制。主要研究内容分为四个方面：转换不同发育阶段（发育温度和产卵温度）温度对寄生蜂行为抉择和生活史的影响，单一发育阶段和多种发育阶段遭受高温热浪对寄生蜂生防潜力的影响评估，不同强度和频率热浪对寄生蜂行为分配和生防潜力的影响。结果表明：转换温度能够显著改变寄生蜂的行为抉择和生活史，表明可以通过转换寄生蜂的发育温度和产卵温度达到改变寄生蜂的生防潜力的目的。热浪处理不仅改变了海氏桨角蚜小蜂的个体发育和生活史参数，同时也影响了寄生蜂的种群参数。幼虫、蛹和成虫三个阶段寄生蜂经历低频率热浪对其内禀增长率和周限增长率的影响不大，但是当高频率热浪作用于寄生蜂幼虫期或蛹期时，寄生蜂内禀增长率和周限增长率显著降低。当同一寄生蜂有两个或两个以上阶段经历高频率热浪时，寄生蜂内禀增长率和周限增长率进一步降低，尤其是幼虫期和蛹期均经历热浪的处理和幼虫期、蛹期和成虫期均经历热浪的处理。热浪的温度强度和发生频率均显著的影响了寄生蜂的行为抉择和生活史参数，证明在田间释放寄生性天敌时需要避免跟热浪气候发生的时间重叠，为在田间释放寄生蜂的时机选择提供了参考。