Chemical Ecology of Swallowtail Butterflies

9420319 Feeny大多数食草昆虫都有特殊的偏好，只在少数几种植物上取食和产卵。它们主要通过植物产生的化学化合物的气味或味道来找到寄主植物。被同一种昆虫攻击的不同植物物种通常具有一种或多种不寻常的化学成分，即使宿主植物本身并不密切相关。这表明，昆虫在食物中添加新植物物种的能力是由昆虫用作线索的化合物的共同出现促进的。这项研究的目的是找出植物之间的化学相似性和差异如何影响当今不同植物物种和以它们为食的昆虫之间的联系。燕尾蝶作为一个模式系统在这项研究中，因为它们的进化关系和幼虫寄主植物是特别众所周知的。这项研究将确定四种昆虫用作产卵刺激剂的植物化合物的混合物，这四种昆虫在它们攻击的植物种类上有很大差异。这些数据将被用来测试昆虫对植物的选择是由对特定化合物的相对固定的感觉反应触发的假设，并且除非这些物种产生相同的化合物，否则不太可能向新的宿主物种移动。这些结果将为昆虫对植物化学物质的感觉反应在进化过程中是保守的而不是不稳定的程度提供有价值的见解。了解昆虫目前用来定位寄主植物的线索，以及昆虫放弃这些线索以利用新寄主的频率，对于明智地部署化学特征已经或可以通过基因工程修改的新作物品种具有明显的意义。

9420319 Feeny Most plant-feeding insects have specialized preferences, feeding and laying their eggs on only a few plant species. They find their host plants largely by smell or taste of chemical compounds produced by the plant. Different plant species attacked by the same insect often share one or more kinds of unusual chemical compounds, even when the host plants themselves are not closely related to one another. This suggests that the ability of insects to add new plant species to their diet is facilitated by the shared occurrence of compounds that the insects use for cues. The goal of this research is to find out how chemical similarities and differences among plants have influenced present-day associations between different plant species and the insects that feed on them. The swallowtail butterflies are used as a model system in this research since their evolutionary relationships and larval host plants are especially well known. The research will identify the mixtures of plant compounds used as egg-laying stimulants by four insect species that differ greatly in the kinds of plants they attack. The data will be used to test the hypotheses that plant selection by insects is triggered by relatively fixed sensory responses to particular compounds, and that movements to new host species are unlikely unless those species produce the same compounds. The results will provide valuable insights into the degree to which sensory responses by insects to plant chemicals are conservative rather than labile over evolutionary time. Knowledge of both the cues insects currently use to locate host plants and the frequency with which insects abandon those cues to take advantage of new hosts has obvious implications for the wise deployment of new crop varieties whose chemical profiles have been or can be modified by genetic engineering.