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

[0104560]目前昆虫和植物之间的联系模式是由于昆虫通过殖民新的寄主植物物种来改变它们可接受的寄主植物范围。然而，使昆虫倾向于“转移”到某些植物而不是其他植物的植物特性却知之甚少。本研究的目的是确定(1)祖先植物和新寄主植物是否共享类似的化学刺激物，从而促进寄主的转移；(2)昆虫对这些化学刺激物的偏好是否具有遗传成分。这将通过调查凤尾蝶群内的宿主转移来完成。蝴蝶将对寄主植物和从这些植物中提取的化学提取物进行测试，以量化对祖先和新寄主植物的偏好。将进行一项遗传性实验，以确定对化学线索的偏好是否是一种可遗传的遗传性状。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寄主的机制。了解昆虫如何将新的寄主纳入它们的饮食是很重要的，因为我们的许多最严重的农业害虫都是通过从原生寄主植物转移到丰富的作物寄主来殖民作物的。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害虫未来的殖民。

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.