The specific subjects of research are the host plant goldenrod (Solidago), the parasitic insect Eurosta solidaginis (Diptera: Tephritidae) that induces a gall on the plant stem, and a number of natural enemies of the gallfly. By presenting their detailed empirical studies of the Solidago-Eurosta natural enemy system, the authors demonstrate the complexities of specialized enemy-victim interactions and, thereby, the complex interactive relationships among species more broadly. By utilizing a diverse array of field, laboratory, behavioral, genetic, chemical, and statistical techniques, Abrahamson and Weis present the most thorough study to date of a single system of interacting species. Their interest in the evolutionary ecology of plant-insect interactions leads them to insights on the evolution of species interactions in general. This major work will interest anyone involved in studying the ways in which interdependent species interact.