Roda A, Nyrop J, Dicke M, English-Loeb G
Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, USA, USA.
Laboratory of Entomology,Wageningen University, P.O. Box 8031, 6700 EH Wageningen, The Netherlands, The Netherlands.
Oecologia. 2000 Nov;125(3):428-435. doi: 10.1007/s004420000462. Epub 2000 Nov 1.
Predaceous arthropods are frequently more abundant on plants with leaves that are pubescent or bear domatia than on plants with glabrous leaves. We explored the hypothesis that for some predatory mites this is because pubescence affords protection from intraguild predation. In laboratory experiments, we tested whether apple leaf pubescence protected Typhlodromus pyri eggs from predation by western flower thrips, Frankliniella occidentalis. To investigate the effect of pubescence further, we added cotton fibers to trichome-free leaves. We also determined whether webbing produced by Tetranychus urticae protected Phytoseiulus persimilis eggs from predation by F. occidentalis. Predation by thrips on T. pyri eggs oviposited on field-collected pubescent "Erwin Bauer" apple leaves was significantly less than on glabrous "Crittenden" apple leaves. Phytoseiid eggs oviposited in the cotton fibers were preyed upon significantly less than those on the trichome-free bean disk. Increasing the cotton fiber density from 5 to 20 fibers only slightly further reduced predation by thrips on T. pyri eggs. Thrips fed upon significantly fewer P. persimilis eggs oviposited in Te. urticae webbing than eggs oviposited on a surface that differed only in the absence of Te. urticae web. We conclude that a complex leaf topography reduces intensity of intraguild predation in this system.
在有具毛或有腔室的叶子的植物上，捕食性节肢动物的数量通常比在叶子无毛的植物上更多。我们探讨了这样一种假说，即对于一些捕食螨来说，这是因为绒毛能提供免受集团内捕食的保护。在实验室实验中，我们测试了苹果叶的绒毛是否能保护梨盲走螨的卵不被捕食性西方花蓟马捕食。为了进一步研究绒毛的影响，我们在无毛的叶子上添加了棉纤维。我们还确定了二斑叶螨产生的丝网是否能保护智利小植绥螨的卵不被捕食性西方花蓟马捕食。蓟马对产在田间采集的具毛“欧文·鲍尔”苹果叶上的梨盲走螨卵的捕食明显少于对无毛“克里滕登”苹果叶上的卵的捕食。产在棉纤维中的植绥螨卵被捕食的情况明显少于产在无毛豆盘上的卵。将棉纤维密度从5根增加到20根只会略微进一步减少蓟马对梨盲走螨卵的捕食。蓟马取食产在二斑叶螨丝网中的智利小植绥螨卵的数量明显少于取食产在仅没有二斑叶螨丝网的表面上的卵的数量。我们得出结论，复杂的叶形降低了该系统中集团内捕食的强度。
