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

Cornell Univ - State: Awds Made Prior May 2010, Ithaca NY

Investigators

Abstract

0104560 Feeny Current 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.