Baur R, Binder S, Benz G
Department of Entomology, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092, Zurich, Switzerland.
Oecologia. 1991 Jul;87(2):219-226. doi: 10.1007/BF00325259.
The grey alder compensates leaf area losses due to insect grazing by continuously producing new leaves throughout the vegetative period. Different degrees of defoliation were attained experimentally by a controlled release of the oligophagous beetle Agelastica alni on arbitrarily selected trees from a homogenous population of young alders. The reduction in leaf area per tree significantly influenced the density of leaf trichomes, assessed 10-30 days later, on newly sprouting leaves only. Cross-correlations between leaf area reduction and trichome density were strongest for leaves which completed unfolding 14-21 days after damage. Dualchoice assays suggested a negative influence of trichomes on oviposition rate of A. alni. Removal of trichomes by shaving demonstrated the highly significant effect of trichomes on feeding behavior of adults and larvae in dual-choice assays. The role of the induced increase in trichome density as a possible short-term defense reaction against herbivorous insects is discussed.
灰桤木通过在整个营养期持续产生新叶来补偿因昆虫啃食造成的叶面积损失。通过在来自均匀的年轻桤木种群中任意选择的树木上控制释放寡食性甲虫桤木叶甲，实验性地实现了不同程度的落叶。每棵树的叶面积减少显著影响了仅在10 - 30天后对新长出叶子上叶毛状体密度的评估。叶面积减少与毛状体密度之间的交叉相关性在受损后14 - 21天展开的叶子中最强。双选试验表明毛状体对桤木叶甲的产卵率有负面影响。通过刮除去除毛状体证明了在双选试验中毛状体对成虫和幼虫取食行为有高度显著的影响。本文讨论了诱导毛状体密度增加作为对食草昆虫可能的短期防御反应的作用。
