天敌昆虫对害虫的非直接致死效应

Non-lethal effects of a natural enemy on herbivore insect population

天敌是影响害虫种群动态的重要因素。一般认为天敌对害虫作用的方式,主要是通过直接的捕食或寄生。事实上,天敌还可以通过捕食或寄生过程中产生的"威吓"等非直接致死效应(Non-lethal effects)或胁迫作用(Stress),影响着害虫的生长发育、繁殖。有时这种天敌存在的非直接致死效应对害虫产生的负面影响甚至比天敌对害虫的直接捕食作用还强。显然,评价天敌作用时,除了计算天敌对害虫的直接捕食或寄生的效率,还应考虑天敌存在时对害虫的非直接致死效应。本文基于作者及前人的研究,分别论述了捕食性天敌、寄生性天敌对害虫的非直接致死效应,解析了环境变化对天敌非直接致死效应的影响,探讨了这种非直接致死效应的可能机制,提出了未来的研究发展方向。

Natural enemies play an important role in regulating the population dynamics of insect pest populations. It is well known that predators typically affect prey through either predation or parasitism. Furthermore, the non-lethal effects, or stress, associated with encountering predators can influence the development and reproduction of pest species. In fact, these non-lethal effects can sometimes have a greater negative influence on pest populations than predation. In view of this, non-lethal effects （indirect stresses） should be taken into account when assessing the control exerted by natural enemies on pest populations. In this paper, we discuss the non-lethal effects of predators and parasites on pest insects, analyze the impacts of changeable environments on the non-lethal effects of natural enemies, summarize the possible mechanisms of non-lethal effects of predators on prey, and provide suggestions for future research on the non-lethal effects of natural enemies on herbivore insect populations.