RUI: Collaborative Research: Host Expansion and Speciation Phytophagous Insects: Behavioral, Ecological, and Genetic Factors

生态学家和进化生物学家提出了草食性昆虫的物种形成模型，这些模型对与寄主植物的遗传、行为和生态相互作用做出了关键假设。检验这些假设将有助于更好地理解植物-食草动物之间的相互作用。如果这些假设在最近分化或正在分化过程中的种群中进行测试，这些测试可以帮助确定几种相互竞争的物种形成模型中哪一种最可信。关于这些假设的假设将在两种密切相关的寄主植物上产生虫害的食草动物的两个种群中进行测试。由于寄主对交配和产卵的偏好不同，这些种群属于同一形态物种，并部分被生殖隔离。对这些偏好的遗传和其他机制的了解，对于理解草食动物物种形成的方式至关重要。这些问题将通过一系列田间、实验园和温室实验来探索。寄主相关种群间杂交的结果将被用来确定寄主和交配地点的偏好以及在不同寄主植物上生存的能力是如何遗传的。将进行更多的实验，以确定环境和经验如何影响产卵和交配地点的偏好。还将进行研究，以确定寄主植物之间的自然选择有何不同，这些寄主植物可以选择种群的差异。最后，一个与寄主相关的种群内是否存在遗传变异，是否可以为转移到新的寄主植物而预先适应行为，将被调查。综上所述，这些数据将提供对植物-食草动物相互作用的生态学、宿主扩张的进化、物种形成以及农业害虫的专门适应的洞察。

Ecologists and evolutionary biologists have proposed speciation models for herbivorous insects that make critical assumptions about genetic, behavior, and ecological interactions with host plants. Testing these assumptions will lead to an improved understanding of plant-herbivore interactions. If these assumptions are tested in populations that have recently diverged, or are in the process of diverging, these tests can help determine which of several competing models of speciation are most plausible. Hypotheses about these assumptions will be tested in two populations of a gall-making herbivore on two closely related host plants. These populations are of one morphological species and are partially reproductively isolated due to differences in host preference for mating and egg-laying. Knowledge of genetic and other mechanisms responsible for these preferences are crucial to understanding how herbivore speciation occurs. These questions will be explored with a series of field, experimental garden, and greenhouse experiments. Results from crosses between the host-associated populations will be used to determine how host-and mating-site preferences and the ability to survive on different host plants is inherited. Additional experiments will be conducted to determine how environment and experience influence oviposition-and mating-site preference. Studies will also be conducted to determine how natural selection differs between host plants that could select for divergence of populations. Finally, whether there is genetic variation within one host-associated population could preadapt the behavior for a shift to a new host plants will be investigated. Taken together, these data will provide insight into the ecology of plant- herbivore interactions, the evolution of host expansions, speciation, as well as the specialized adaptations of agricultural pests.