My research focuses on the ecology and evolutionary biology of herbivorous insects. My main interests center on understanding the determinants of the genetic differentiation of populations. Thus, I have examined the influence of temporal isolation, geographic isolation, dispersal strategies, and diet breadth on the degree to which populations are genetically subdivided. Currently, I am using this perspective to understand the evolution of reproductive barriers between hybridizing beetles. A second area of interest focuses on how mutualistic interactions influence both the population dynamics and community structure of herbivorous insect species on desert willows.