Department of Plant, Soil and Entomological Sciences, Agric. Sci. 242, University of Idaho, Moscow, Idaho 83844-2339.
Integr Comp Biol. 2002 Dec;42(6):1091-9. doi: 10.1093/icb/42.6.1091.
Insects foraging on plant surfaces must attach to the layer of lipophilic materials known as epicuticular waxes (EW) that cover these surfaces. In this paper, we briefly review the evidence that variation in EW morphology can influence the ecology of herbivorous insects directly, by affecting their attachment to plant surfaces, and indirectly by affecting attachment by actively foraging predatory insects to plant surfaces. We then present new data examining how EW micromorphology and chemical composition of Brassica oleracea influence attachment by the predatory beetle, Hippodamia convergens (Coccinellidae). Bioassays with genotypes of B. oleracea differing in wax characteristics, and with EW extracts from these plants applied to glass, show that wax crystals disrupt attachment. In addition, bioassays show that attachment by H. convergens differs among EW extracts prepared to have smooth surfaces without crystals. The differences in attachment under these conditions are evidently due to the chemical composition of the waxes. Bioassays with two pure wax constituents show that wax composition can significantly affect attachment by H. convergens. The study opens the way for using a similar approach to understand attachment by insects to waxy plant surfaces.
昆虫在植物表面觅食时，必须附着在覆盖这些表面的亲脂性物质——俗称表皮蜡质（EW）的层上。在本文中，我们简要回顾了证据，证明 EW 形态的变异可以直接通过影响它们对植物表面的附着，间接地通过影响积极觅食的捕食性昆虫对植物表面的附着，从而影响食草昆虫的生态学。然后，我们提出了新的数据，研究了芸薹属植物表皮蜡质的微观形态和化学成分如何影响捕食性甲虫 Hippodamia convergens（瓢虫科）的附着。用蜡质特性不同的芸薹属基因型进行生物测定，并将这些植物的 EW 提取物涂在玻璃上，结果表明蜡晶体破坏了附着。此外，生物测定还表明，在没有晶体的光滑表面上制备的 EW 提取物之间，附着方式存在差异。在这些条件下，附着的差异显然是由于蜡的化学成分造成的。用两种纯蜡成分进行的生物测定表明，蜡的组成可以显著影响 Hippodamia convergens 的附着。这项研究为使用类似的方法来理解昆虫对蜡质植物表面的附着开辟了道路。
