Kimberling D N, Price P W
Department of Biological Sciences, Northern Arizona University, NAU. Box 5640, 86011, Flagstaff, AZ, USA.
Oecologia. 1996 Sep;107(4):553-559. doi: 10.1007/BF00333948.
We tested the deme-formation hypothesis experimentally with four populations of leaf-galling grape phylloxera, Daktulosphaira vitifoliae, and its host, canyon grape (Vitis arizonica). An experiment designed to examine preference and performance showed that phylloxera populations did not significantly prefer their original host relative to other hosts in the percent available leaves galled. There were significant herbivore population effects (P<0.01), host effects (P<0.001), and population x host interaction effects (P<0.001). Herbivore populations had different colonizing abilities (performance, as measured in the mean number of galls per leaf) on an individual host (P<0.001), but there was no host effect. Host genotype significantly affected phylloxera performance, measured as survivorship (P<0.01), but a phylloxera population did not necessarily have higher survivorship on its original host. Differences in fecundity, an-other measurement of performance, were due to intrinsic differences among herbivore populations (P<0.05), and not related to host genotype. There was no correlation between distance from a phylloxera population in the field and a host's susceptibility to attack. There was a significant positive relationship between levels of infestation on a clone in the field and its susceptibility to colonization experimentally (P<0.05), suggesting inherent differences in host resistance and susceptibility. These results did not support the deme-formation hypothesis. In a second experiment, host clone x water treatment interactions affected phylloxera survivorship (P<0.05) and fecundity (P<0.05). We conclude that host genotype x environment interactions may prevent sessile, parthenogenetic herbivores from locally adapting to individual host genotypes.
我们用四个叶瘿葡萄根瘤蚜种群及其寄主峡谷葡萄（Vitis arizonica）对种群形成假说进行了实验测试。一项旨在研究偏好和表现的实验表明，相对于其他寄主，葡萄根瘤蚜种群在被瘿害的可用叶片百分比方面，对其原始寄主并没有显著偏好。存在显著的食草动物种群效应（P<0.01）、寄主效应（P<0.001）以及种群×寄主交互效应（P<0.001）。食草动物种群在单个寄主上具有不同的定殖能力（表现，以每片叶上的瘿平均数量衡量）（P<0.001），但不存在寄主效应。寄主基因型显著影响葡萄根瘤蚜的表现，以存活率衡量（P<0.01），但葡萄根瘤蚜种群在其原始寄主上的存活率不一定更高。繁殖力差异是表现的另一种衡量方式，这是由于食草动物种群之间的内在差异所致（P<0.05），与寄主基因型无关。田间葡萄根瘤蚜种群与寄主对攻击的易感性之间没有相关性。田间一个克隆上的侵染水平与其在实验中的定殖易感性之间存在显著的正相关关系（P<0.05），表明寄主抗性和易感性存在内在差异。这些结果不支持种群形成假说。在第二项实验中，寄主克隆×水处理交互作用影响了葡萄根瘤蚜的存活率（P<0.05）和繁殖力（P<0.05）。我们得出结论，寄主基因型×环境交互作用可能会阻止固着的、孤雌生殖的食草动物在局部适应单个寄主基因型。
