Research Interests The focus of my research is the community and evolutionary ecology of plant resistance and tritrophic interactions in terrestrial plant-herbivore systems. Plant resistance to herbivores is a set of complex traits, some or all of which influence the impact of individual herbivore species on plant fitness. However, almost every plant species interacts with a number of herbivore species. In turn, those herbivore species are influenced by their own natural enemies. Therefore, understanding the evolution of plant resistance requires in part a community-level, tritrophic approach. Furthermore, interactions amongst herbivore species themselves, whether competitive or mutualistic, can be mediated through their use of the host plant as a resource. The influence of plant traits on such interactions and on herbivore community structure, and their resultant impact on damage to the plant, are subjects of my current experimentation. Thus, my research focuses on the interaction between host plant traits and the community of insects associated with the plant, their interactions with their natural enemies, and interactions amongst the herbivores themselves, all as they affect plant fitness components. My current projects include the study of importance of plant traits on the impacts of leaf-tying caterpillars on arthropod structure of Missouri oaks (with George Wang and Rick Lankau), evolution of plant resistance traits in the ant-tended Chamaecrista fasciculata, the impact of plant phylogeny on herbivore and associated parasitoid communities of Canadian trees, the influence of latitude versus phylogeny on leaf and wood traits of woody plant species, and role of stem-boring beetles as ecosystem engineers in Brazilian cerrado trees (with Drs. Scott Powell, Kleber Del Claro, and Heraldo Vasconcellos(. In addition, I have been sampling herbivorous insects on oaks since 1991 as part of the Missouri Ozark Forest Ecosystem Project (MOFEP) (http://mofep.mdc.mo.gov/). The goal of this project is to determine the longterm impacts of forest management on biodiversity and ecosystem functioning. Email Phone: 314-516-6213http://mofep.mdc.mo.gov/mailto:robert_marquis@umsl.edu?subject=Dear%20Bobshapeimage_2_link_0shapeimage_2_link_1