Evolutionary Ecology of Black Pineleaf Scale Infestations on Ponderosa Pine

黑松蚧（Nuculaspis californica 科尔曼）是西方黄松（Pinus ponderosa）的寄生虫 劳森 这些昆虫相对于它们的宿主来说是短命的， 它们的种群被细分， 在极短的距离内发生基因分化 与两个单独的宿主树相关联， 一棵松树内的树枝（阿尔斯塔德和科尔宾，出版中）。 最近的研究得出了三种不同的证据 （Alstad and Edmunds 1989，Alstad and Corbin in press，Alstad 未发表的）与我们先前的观点相妥协（埃德蒙兹和阿尔斯塔德 1978，1981; Alstad和Edmunds（1983 a，1983 b）， 人口结构反映了规模的适应， 个体宿主树的内在基因型特征。 这项拟议中的研究将测试一个新的假设， 黑松林局部分化的机制 危害美国黄松蚧虫：蚧的适应 与外在表型性状相关的选择结果 其中（a）是松树和松树之间相互作用的产物， 基因型和它的环境，和（B）内和 树之间。 这些对立的假设代表了 在植物/食草动物相互作用的文献中;它们是 进化生态学家的基本兴趣，并有明确的， 对森林管理的重要影响。

The black pineleaf scale insect (Nuculaspis californica Coleman) is a parasite of western yellow pine (Pinus ponderosa Lawson. The insects are shortlived relative to their host and largely sedentary, and their populations are subdivided and genetically differentiated over extraordinarily short distances in association with both individual host trees, and different branches within a single pine (Alstad and Corbin, in press). Three different kinds of evidence resulting from recent research (Alstad and Edmunds 1989, Alstad and Corbin in press, and Alstad unpublished) compromise our earlier view (Edmunds and Alstad 1978, 1981; Alstad and Edmunds 1983a, 1983b) that scale population structure reflects adaptation of the scale demes to intrinsic, genotypic characteristics of individual host trees. The proposed research will test a new hypothesis about the mechanistic causes of local differentiation in black pineleaf scale insects infesting ponderosa pine: that scale adaptation results from selection related to extrinsic phenotypic traits which (a) are the product of interactions between the pine genotype and its environment, and (b) vary both within and between trees. These opposing hypotheses represent major themes in the literature of plant/herbivore interactions; they are of basic interest to evolutionary ecologists and have clear and important implications for forest management.