Shirotsuka Kanako, Yano Shuichi
Laboratory of Ecological Information, Department of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan,
Exp Appl Acarol. 2012 Jan 29. doi: 10.1007/s10493-012-9514-4.
Intraguild predation (IGP) is defined as the killing and eating of prey species by a predator that also can utilize the resources of the prey. It is mainly reported among carnivores that share common herbivorous prey. However, a large chewing herbivore could prey upon sedentary and/or micro herbivores in addition to utilizing a host plant. To investigate such coincidental IGP, we observed the behavioral responses of the polyphagous mite Tetranychus kanzawai Kishida (Acari: Tetranychidae) when its host plant Cayratia japonica (Thunb.) Gagnep. (Vitaceae) was attacked by hornworms, Theretra japonica Boisduval (Sphingidae) and T. oldenlandiae Fabricius (Sphingidae). We also examined an interaction between the oligophagous mite Panonychus citri McGregor (Acari: Tetranychidae) and caterpillars of the swallowtail Papilio xuthus L. (Papilionidae) that share citrus plants as their main food source. Although all T. kanzawai and some active stage P. citri tried to escape from the coincidental IGP, some were consumed together with eggs, quiescent mites, and host plant leaves, suggesting that coincidental IGP occurs on spider mites in the wild. Moreover, neither hornworms nor swallowtail caterpillars distinguished between spider mite-infested and uninfested leaves, suggesting that the mite-infested leaves do not discourage caterpillar feeding. The reasons that the mites have no effective defense against coincidental IGP other than escaping are discussed.
集团内捕食（IGP）的定义是，一种捕食者杀死并吃掉猎物物种，而该捕食者也能够利用猎物的资源。这种现象主要报道于共享常见食草猎物的食肉动物之间。然而，除了利用寄主植物外，大型咀嚼式食草动物还可能捕食定居型和/或小型食草动物。为了研究这种巧合性的集团内捕食现象，我们观察了多食性螨类神泽氏叶螨（Tetranychus kanzawai Kishida，蜱螨目：叶螨科）在其寄主植物乌蔹莓（Cayratia japonica (Thunb.) Gagnep.，葡萄科）受到天蛾，即芋双线天蛾（Theretra japonica Boisduval，天蛾科）和变色天蛾（T. oldenlandiae Fabricius，天蛾科）攻击时的行为反应。我们还研究了寡食性螨类柑橘全爪螨（Panonychus citri McGregor，蜱螨目：叶螨科）与以柑橘植物为主要食物来源的凤蝶科昆虫柑橘凤蝶（Papilio xuthus L.）幼虫之间的相互作用。尽管所有的神泽氏叶螨和一些处于活动阶段的柑橘全爪螨试图逃离这种巧合性的集团内捕食，但一些螨与卵以及静止期螨类和寄主植物叶片一起被吃掉，这表明在野外叶螨中存在巧合性的集团内捕食现象。此外，天蛾幼虫和凤蝶幼虫都没有区分叶螨侵染和未侵染的叶片，这表明被螨侵染的叶片不会阻碍幼虫取食。文中还讨论了螨类除了逃脱之外，对巧合性集团内捕食没有有效防御的原因。
