Recent studies have shown that genetic polymorphisms play an important role in structuring the seasonal life cycles of insects, complementing an earlier emphasis on the effects of environmental factors. This book presents current ideas and recent research on insect life—cycle polymorphism in a series of carefully prepared chapters by international experts, covering the full breadth of the subject in order to give an up-to-date view of how life cycles are controlled and how they evolve. By consolidating our view of insect life—cycle polymorphism in this way, the book provides a staging point for further enquiries. The volume will be of interest to a wide variety of entomologists and other biologists interested in the control and evolution of life cycles and in understanding the extraordinarily complex ecological strategies of insects and other organisms.