BIOGECO, INRA, Univ. Bordeaux, 33610, Cestas, France.
Misión Biológica de Galicia (MBG-CSIC), Apartado de correos 28, 36080, Pontevedra, Galicia, Spain.
Sci Rep. 2018 Apr 12;8(1):5930. doi: 10.1038/s41598-018-24299-x.
Both plant neighbourhood composition and drought have well-known independent effects on insect herbivore performance, but their interactive effects remain elusive. In this study we performed a laboratory experiment to investigate the independent and combined effects of plant neighbourhood composition and drought on the performance of Gypsy moth larvae (Lymantria dispar) feeding on silver birch (Betula pendula) leaves. For this, we collected leaf samples from birch trees growing in a field experiment where we manipulated both host-tree species diversity (three levels: birch monocultures, two-species mixtures associating birch with the pedunculate oak Quercus robur or maritime pine Pinus pinaster, and three-species mixture with pedunculate oak, the maritime pine and birch) and water availability (two levels: irrigated vs. non-irrigated). In most cases, plant neighbourhood composition and irrigation treatments independently and interactively affected herbivore performance traits, especially those related to growth and food (i.e. birch leaves) processing. By addressing the interactive effects of tree species diversity and drought on insect herbivory from the herbivore's point of view, our study builds toward a better understanding of the multiple ecological drivers of plant-insect interactions.
植物邻域组成和干旱对昆虫食草动物的表现都有众所周知的独立影响，但它们的交互作用仍然难以捉摸。在这项研究中，我们进行了一项实验室实验，以研究植物邻域组成和干旱对以银桦（Betula pendula）叶为食的舞毒蛾幼虫（Lymantria dispar）表现的独立和综合影响。为此，我们从生长在田间实验中的桦树中收集叶片样本，在该实验中，我们同时操纵了两个方面：一是寄主树种多样性（三个水平：桦树纯林、与欧洲山毛榉或地中海柏木组合的两种树种混合物、以及包含欧洲山毛榉、地中海柏木和桦树的三种树种混合物），二是水的可用性（两个水平：灌溉与非灌溉）。在大多数情况下，植物邻域组成和灌溉处理独立且相互作用地影响食草动物的表现特征，特别是与生长和食物（即桦树叶）处理相关的特征。从食草动物的角度出发，通过解决树种多样性和干旱对昆虫食草作用的相互作用，我们的研究有助于更好地理解植物-昆虫相互作用的多种生态驱动因素。
