Book excerpt: It helps to explain such notable phenomena as castes in social insects, phase shifts in locusts, alternation of generations in aphids, color polymorphism in butterflies, allometry and horn length in beetles, and diapause, estivation, quiescence, acclimation, learning, migration, host plant switching, alternative mating tactics, and maternal effects, in a wide range of insects. This book documents the plasticity inherent in insects. In a companion volume, Phenotypic Plasticity of Insects: Mechanisms and Consequences we explore the underlying causes, process, and consequences of plasticity."--Jacket.