Native generalist natural enemies and an introduced specialist parasitoid together control an invasive forest insect

Specialized natural enemies have long been considered a major force driving the population dynamics of outbreaking forest insects. While research has traditionally focused on the role of specialist parasitoids, recent studies and reviews reflect an appreciation of complex interactions among many regulatory factors. The sources suggest that specialist parasitoids and generalist predators can each inflict strong top‐down effects and that specialists and generalists can interact to regulate insect herbivore populations. Here we use the model study organism winter moth (Operophtera brumata) in its invasive range in the northeast United States to investigate interactions between the introduced, host-specific tachinid parasitoid Cyzenis albicans and native, generalist pupal predators. Prior research in Canada showed that predation of winter moth pupae increased after C. albicans establishment. To explain this phenomenon, the following hypotheses have been suggested: (1) parasitoids suppress t...专性天敌（specialized natural enemies）长期以来被认为是驱动爆发性森林昆虫种群动态的核心驱动力。尽管传统研究多聚焦于专性寄生蜂（specialist parasitoids）的调控作用，近期研究与综述则凸显了多种调控因子间复杂互作的重要性。相关研究表明，专性寄生蜂与广食性捕食者均可产生显著的顶下行效应（top-down effects），且专性天敌与广食性天敌的交互作用可共同调控植食性昆虫种群。本研究以入侵至美国东北部的模式生物冬尺蛾（Operophtera brumata）为研究对象，探究引入的宿主特异性寄蝇科寄生蜂Cyzenis albicans与本土广食性蛹期捕食者之间的互作关系。此前在加拿大开展的研究显示，Cyzenis albicans定殖后，冬尺蛾蛹的捕食率显著提升。为解释该现象，学界提出了以下假说：(1) 寄生蜂抑制t...