Venzon M, Janssen A, Sabelis M W
IBED, Section Population Biology, University of Amsterdam, P.O. Box 94084, 1090 GB Amsterdam, The Netherlands.
Exp Appl Acarol. 2001;25(10-11):785-808. doi: 10.1023/a:1020443401985.
The theory of intraguild predation (IGP) largely studies effects on equilibrium densities of predators and prey, while experiments mostly concern transient dynamics. We studied the effects of an intraguild (IG) predator, the bug Orius laevigatus, on the population dynamics of IG-prey, the predatory mite Phytoseiulus persimilis, and a shared prey, the phytophagous two-spotted spider mite Tetranychus urticae, as well as on the performance of cucumber plants in a greenhouse. The interaction of the predatory mite and the spider mite is highly unstable, and ends either by herbivores overexploiting the plant or predators exterminating the herbivores. We studied the effect of IGP on the transient dynamics of this system, and compared the dynamics with that predicted by a simple population-dynamical model with IGP added. Behavioural studies showed that the predatory bug and the predatory mite were both attracted to plants infested by spider mites and that the two predators did not avoid plants occupied by the other predator. Observations on foraging behaviour of the predatory bug showed that it attacks and kills large numbers of predatory mites and spider mites. The model predicts strong effects of predation and prey preference by the predatory bugs on the dynamics of predatory mites and spider mites. However, experiments in which the predatory bug was added to populations of predatory mites and spider mites had little or no effect on numbers of both mite species, and cucumber plant and fruit weight.
集团内捕食（IGP）理论主要研究对捕食者和猎物平衡密度的影响，而实验大多关注瞬态动态。我们研究了集团内（IG）捕食者，即糙脉姬猎蝽，对IG猎物（即捕食性螨类智利小植绥螨）和共享猎物（即植食性二斑叶螨）种群动态的影响，以及对温室黄瓜植株生长表现的影响。捕食性螨类和叶螨之间的相互作用极不稳定，要么以食草动物过度啃食植物告终，要么以捕食者消灭食草动物告终。我们研究了集团内捕食对该系统瞬态动态的影响，并将这些动态与添加了集团内捕食的简单种群动态模型预测的动态进行了比较。行为学研究表明，捕食性蝽和捕食性螨都被叶螨侵染的植物所吸引，而且这两种捕食者不会避开被另一种捕食者占据的植物。对捕食性蝽觅食行为的观察表明，它会攻击并杀死大量捕食性螨和叶螨。该模型预测，捕食性蝽的捕食和猎物偏好对捕食性螨和叶螨的动态有强烈影响。然而，将捕食性蝽添加到捕食性螨和叶螨种群中的实验对这两种螨类的数量以及黄瓜植株和果实重量几乎没有影响。
