This monograph, a set of 2 volumes places greater emphasis on the biology, behavior, and evolution of the gall-inducing arthropod and of associated organisms; the dynamics of the host-plant response remain in the background. The book deals with the biology and ecology of acarines, hemipteroids, coleopteroids and hymenopteroids. It also includes chapters on the biology, ecology, and evolution of several minor or less-known groups of gall inducers. A special effort has been made to incorporate extensive chapters on gall-inducing Coleoptera, chloropids, and chalcidoids including the braconids and fig wasps. Chapters on whiteflies and dipteran leafminers should broaden our understanding of the galling habit in other groups of arthropods. In addition to the biological and ecological informa-tion on these arthropods, each chapter also provides information on their evolution, in most instances, viewed against the evolution of their host plants.