Insect Photoperiodism reviews the many aspects of photoperiodism, particularly in insects, emphasizing the concepts that serve to place the subject in a meaningful relationship to the whole of modern biology. Photoperiodism is the study of the adaptive mechanisms by which living systems exploit this source of temporal information. Organized into 12 chapters, this book begins by discussing the relationships between an endogenous behavioral rhythm and the exogenous photoperiod. Aside from behavioral activities, it also shows that some observable developmental events tend to occur at species-typical times of the day and to be photoperiodically regulated. Notably, photoperiod may exert either or both of two regulatory effects on insect development: growth rate effects or polymorphism. Furthermore, the characteristics of some of the principal physiological rhythms that have been studied; role of photoperiod in the control of diapauses; and the circadian functions and theoretical nature of biological clock are explored in this book.