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

产卵昆虫通常根据叶片表面的化合物做出最终的寄主选择决定。人们对叶片表面的化学成分以及叶片表面化学成分的变化与昆虫选择寄主的关系知之甚少。该项目的目标是研究单一植物物种（胡萝卜）的叶表面化学，特别是参考已经确定为其专业食草昆虫之一（凤蝶）的产卵刺激物的化合物。植物表面将用氯仿和近沸水的混合物提取，所得提取物将用高效液相色谱法进行分离和分析。该项目将包括：(1)比较不同年龄、形态、生活史和基因型叶片的表面化学特征；(2)比较不同植物作为产卵基质的表面化学特征；(3)不同基因型植物产卵可接受性的幼虫性能比较。这些实验应该确定在何种程度上叶表面化学变化与昆虫的产卵偏好和随后的幼虫性能相关。本研究将揭示叶片表面的化学信号是否可以作为雌蝶产卵识别优质寄主地点的关键。

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.