Collaborative Research: Mating Signals and Demographic Divergence: Species Comparisons and Experimental Tests

Cocroft，Hunt和WoodMating信号可以在物种形成过程的早期发生分歧，但目前还不清楚信号分歧是否在物种形成中起直接作用，或者是其他过程（如生态专业化）的副产品。 我们的目标是确定交配信号在一组食草昆虫多样化中的作用。 Enchenopa binotata物种复合体由9种树跳组成，它们是北美各种树木和灌木的专家。 相当多的证据表明，在这组物种的发生作为一系列的变化，以新的寄主植物。 宿主转移改变了生活史的时间，这与高宿主保真度相结合，允许在增强新宿主性能的性状上出现分歧。 我们的研究将测试的假设，交配信号的分歧是重要的物种形成，减少祖先和新的宿主植物种群之间的基因流。 我们的项目将整合（1）在九个现存Enchenopa binotata物种的振动交配信号的比较研究;（2）在物种内和物种之间的DNA序列差异模式的信号变化模式的比较;和（3）在信号和生活史性状的分歧是否发生在实验主机转移人口的确定。 这项研究将提供一个互补的图片交配信号和分歧之间的关系，不仅在完全分化的物种，而且在谱系在寄主植物种族形成的早期阶段。这项研究的结果将增强我们对物种形成的基本理解，并可能提供实际利益，例如更好地了解农业害虫如何在新的宿主物种上建立。

Lay SummaryCocroft, Hunt and WoodMating signals can diverge early in the process of speciation, but it is unclear whether signal divergence plays a direct role in speciation or is a byproduct of other processes such as ecological specialization. Our goal is to determine the role of mating signals in the diversification of a group of plant-feeding insects. The Enchenopa binotata species complex of treehoppers consists of nine species that are specialists on various trees and shrubs in North America. Considerable evidence suggests that speciation in this group occurred as a result of a series of shifts to novel host plants. A host shift alters life history timing, which, in combination with high host fidelity, allows divergence in traits that enhance performance on a novel host. Our research will test the hypothesis that divergence in mating signals is important in speciation by reducing gene flow between populations on ancestral and novel host plants. Our project will integrate (1) a comparative study of vibrational mating signals in the nine extant Enchenopa binotata species; (2) comparison of patterns of signal variation within and among species with patterns of DNA sequence divergence; and (3) determination of whether divergence in signals and life history traits has occurred in experimentally host-shifted populations. This research will provide a complementary picture of the relationship between mating signals and divergence not only in fully differentiated species, but also in lineages in the early stages of host plant race formation. Results of this research will enhance our basic understanding of speciation, and may provide practical benefits such as an improved understanding of how agricultural pests become established on novel host species.