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

Feeny 9700718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。人们对叶表面的化学成分知之甚少，也不知道叶表面化学成分的变化如何与昆虫对寄主的选择有关。该项目的目标是研究单一植物物种(胡萝卜属)的叶表面化学成分，特别是已被确定为其一种专门的食草性昆虫(多雄凤头蝶)产卵刺激剂的化合物。植物表面将用氯仿和近沸水的组合进行提取，得到的萃取物将进行分级，并使用高效液相色谱进行分析。该项目将包括：(1)不同年龄、形态、生活史和基因型的叶片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；以及(3)不同产卵能力不同植物基因的幼虫表现的比较。这些实验应该确定叶表面化学变化与昆虫种类的产卵偏好和随后的幼虫表现之间的关联程度。这项研究将揭示叶表面的化学信号是否可以作为识别产卵雌性蝴蝶的优质寄主位置的关键。

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.