Dissertation Research: Chemical Signals on Leaf Surfaces: Keys to Recognition by Ovipositing Insects

产卵昆虫通常根据叶表面存在的化合物做出最终的寄主选择决定。关于叶表面的化学性质以及表面化学特征的变化如何与昆虫的寄主选择有关，人们知之甚少。该项目的目标是研究一个单一的植物物种（胡萝卜）的叶表面化学，特别是参考化合物已经确定为产卵兴奋剂的一个专业昆虫食草动物（凤蝶）。植物表面将用氯仿和近沸水的组合提取，所得提取物用高效液相色谱法分级和分析。该项目将包括：（1）年龄、形态、生活史和基因型不同的叶片的表面化学特征的比较;（2）作为产卵基质的可接受性不同的植物的表面化学特征的比较;和（3）在产卵可接受性不同的植物基因型上的幼虫表现的比较。这些实验应确定在何种程度上叶面化学变化与产卵的昆虫物种和随后的幼虫性能的偏好。这项研究将揭示叶片表面的化学信号是否可以作为产卵雌蝶识别优质寄主场所的关键。

Feeny 9700718 Ovipositing insects generally make final host-selection decisions on the basis of compounds present on the leaf surface. Little is known about the chemistry of leaf surfaces and how variation in surface-chemical profiles is related to host selection by insects. The goal of this project is to examine the leaf-surface chemistry of a single plant species (Daucus carota) with particular reference to compounds already identified as oviposition stimulants for one of its specialist insect herbivores (Papilio polyxenes). Plant surfaces will be extracted with a combination of chloroform and near-boiling water, and the resulting extracts fractionated and analyzed using high performance liquid chromatography. The project will include: (1) comparisons of the surface-chemical profiles of leaves differing in age, form, life history and genotype; (2) comparisons of the surface-chemical profiles of plants differing in acceptability as oviposition substrates; and (3) comparisons of larval performance on plant genotypes differing in oviposition acceptability. These experiments should determine the extent to which leaf-surface chemical variation is correlated with oviposition preferences of an insect species and subsequent larval performance. This research will reveal whether chemical signals on leaf surfaces can serve as keys for recognition of quality host sites by ovipositing female butterflies.