The link between herbivore damage levels and plant population dynamics has not been made for many species. It is especially interesting to explore these links in introduced species that may have escaped a large suite of adapted specialist herbivores. Several hypotheses (EICA and the Enemy Release Hypothesis) suggest that escape from herbivores plays a large role in the evolution and spread of introduced species in novel habitats. I examine the impact of experimentally manipulated herbivory levels on radish population density over the course of a multi-year field experiment at Bodega Bay, CA. Based on preliminary analysis, my data suggest that herbivores limit densities of this introduced species in its novel range.