Dissertation Research: A Host Shift by Swallowtail Butterflies Within the Papilio machaon Species Group: The Role of Plant Chemistry

目前昆虫与植物之间的关系模式是由昆虫通过在新的寄主植物物种中定殖来改变其可接受的寄主植物范围的事件引起的。 然而，使昆虫倾向于“转移”到某些植物而不是其他植物上的植物性状却知之甚少。 本研究的目的是确定（1）祖先和新的宿主植物是否具有相似的化学刺激物，这将促进宿主转移，以及（2）昆虫对这些化学信号的偏好是否具有遗传成分。 这将通过调查凤蝶属燕尾蝶组内的宿主转移来完成。 蝴蝶将在宿主植物和从这些植物中提取的化学提取物上进行测试，以量化对祖先和新宿主植物的偏好。 将进行遗传性实验以确定对化学线索的偏好是否是可遗传的遗传性状。 这些实验将确定植物化学是否可以作为昆虫识别新植物物种作为潜在宿主的机制。 了解昆虫如何将新宿主纳入其饮食是很重要的，因为我们许多最严重的农业害虫已经通过从本地宿主植物转移到丰富的作物宿主来殖民作物。 因此，了解植物化学如何影响昆虫转向新宿主的决定可能有助于减少未来害虫的定植。

0104560FeenyCurrent patterns of association between insects and plants have resulted from events in which insects modify their range of acceptable host plants by colonizing novel host-plant species. However, the plant traits that predispose insects to "shift" onto some plants instead of others are poorly understood. The goals of this research are to determine (1) if ancestral and novel host plants share similar chemical stimulants that would facilitate a host shift and (2) if insect preference for these chemical cues has a genetic component. This will be accomplished by investigating a host shift within the Papilio machaon group of swallowtail butterflies. Butterflies will be tested on host plants and chemical extracts made from these plants to quantify preference for ancestral and novel host plants. A heritability experiment will be performed to determine if preference for chemical cues is a heritable genetic trait. These experiments will determine whether plant chemistry can act as a mechanism for insects to recognize new plant species as potential hosts. Understanding how insects incorporate new hosts into their diets is important because many of our worst agricultural pests have colonized crop plants by shifting from a native host plant to an abundant crop host. Therefore, learning how plant chemistry can affect an insect's decision to shift to a novel host may help to reduce future colonizations by insect pests.