烟盲蝽对不同密度斜纹夜蛾初龄幼虫的捕食和搜寻行为

为评价动植食性烟盲蝽对害虫的控制作用，本文通过室内试验研究了烟盲蝽在斜纹夜蛾幼不同密度虫斑块上的捕食和搜寻行为。在盆栽烟草植株上设置不同猎物密度，每株分别接0、5、10、20和30头1龄斜纹夜蛾幼虫于同一叶片上，然后接入1头烟盲蝽雌成虫，观察记录烟盲蝽的行为及其发生时间。结果表明，烟盲蝽对猎物的捕食量随猎物密度增大而增加；对猎物被捕食的时间进行Cox比例风险模型拟合表明，低密度猎物斑块上的幼虫被烟盲蝽捕食的风险大于高密度猎物斑块。烟盲蝽在猎物斑块上的行为以搜寻和刺吸猎物、植物为主，用于梳理和休息的时间较少；在低密度猎物斑块上，搜寻和刺吸植物的时间占较大比例；而在高密度猎物斑块上，刺吸猎物的时间占较大比例。烟盲蝽在斑块上的驻留时间随猎物密度增大而延长，在高密度猎物斑块上的驻留时间显著长于在低密度斑块上。研究结果说明，烟盲蝽对斜纹夜蛾初龄幼虫的捕食强度与猎物密度有关，密度越高，捕食得越多，但花费的时间更多，从而导致对高密度猎物的捕食效率低于对低密度猎物的捕食。

Predation Behaviors of Nesidiocoris tenuis on Neonate Larvae of Spodoptera litura at Different Densities

To evaluate the role of zoophytophagous predator mirid Nesidiocoris tenuis (Reuter) in insect pest control, a laboratory trial was conducted to examine the predation behaviors of N. tenuis female adults that were individually provided with first instar larvae of Spodoptera litura at the density of either 0, 5, 10, 20, or 30 larvae on a tobacco leaf. The number of caterpillars preyed by N. tenuis increased with the increase in prey density. Cox proportion hazard model fit showed that the risk of S. littura larvae being preyed was higher at low prey densities than at high prey densities. The predator spent more time on searching, capturing, and plant-feeding on low prey density patches, but less time on grooming and resting. The predator spent more time in searching and plant-feeding, but more time in prey-capturing on higher density prey patches. Patch residence time increased with the increase in prey density. The results suggested that N. tenuis can prey more neonate larvae of S. litura on high density prey-patches by spending longer time, leading however to lower predation efficiency.