Life evolves in a cyclic environment, and to be successful, organisms must adapt not only to their spatial habitat, but also to their temporal habitat. How do plants and animals determine the time of year so they can anticipate seasonal changes in their habitats? In most cases, day length, or photoperiod, acts as the principal external cue for determining seasonal activity. For organisms not living at the bottom of the ocean or deep in a cave, day follows night, and the length of the day changes predictably throughout the year. These changes in photoperiod provide the most accurate signal for predicting upcoming seasonal conditions. Measuring day length allows plants and animals to anticipate and adapt to seasonal changes in their environments in order to optimally time key developmental events including seasonal growth and flowering of plants, annual bouts of reproduction, dormancy and migration in insects, and the collapse and regrowth of the reproductive system that drives breeding seasons in mammals and birds.
Although research on photoperiodic time measurement originally integrated work on plants and animals, recent work has focused more narrowly and separately on plants, invertebrates, or vertebrates. As the fields have become more specialized there has been less interaction across the broader field of photoperiodism. As a result, researchers in each area often needlessly repeat both theoretical and experimental work. For example, understanding that there are genetically distinct morphs among species that, depending on latitude, respond to different critical photoperiods was discovered separately in plants, invertebrates, and vertebrates over the course of 20 years. However, over the past decade, intense work on daily and seasonal rhythms in fruit flies, mustard plants, and hamsters and mice, has led to remarkable progress in understanding the phenomenology, as well as the molecular and genetic mechanisms underlying circadian rhythms and clocks. This book was developed to further this type of cooperation among scientists from all related disciplines. It brings together leading researchers working on photoperiodic timing of seasonal adaptations in plants, invertebrates, and vertebrates. Each of its three sections begins with an introduction by the section editor, and at the end of the book, the section editors present a synthesis of common themes in photoperiodism, as well as discuss similarities and differences in approaches to the study of photoperiodism, and future directions for research on photoperiodic time measurement.

This book focuses on an array of integrated pest management tools (IPM) that exploit extreme temperatures, examining the biological basis for using temperature extremes in controlling insects and presenting practical IPM techniques that rely on temperature.

This book focuses on an array of integrated pest management tools (IPM) that exploit extreme temperatures, examining the biological basis for using temperature extremes in controlling insects and presenting practical IPM techniques that rely on temperature.

Low temperature is a major environmental constraint impacting the geographic distribution and seasonal activity patterns of insects. Written for academic researchers in environmental physiology and entomology, this book explores the physiological and molecular mechanisms that enable insects to cope with a cold environment and places these findings into an evolutionary and ecological context. An introductory chapter provides a primer on insect cold tolerance and subsequent chapters in the first section discuss the organismal, cellular and molecular responses that allow insects to survive in the cold despite their, at best, limited ability to regulate their own body temperature. The second section, highlighting the evolutionary and macrophysiological responses to low temperature, is especially relevant for understanding the impact of global climate change on insect systems. A final section translates the knowledge gained from the rest of the book into practical applications including cryopreservation and the augmentation of pest management strategies.

Our highly seasonal world restricts insect activity to brief portions of the year. This feature necessitates a sophisticated interpretation of seasonal changes and enactment of mechanisms for bringing development to a halt and then reinitiating it when the inimical season is past. The dormant state of diapause serves to bridge the unfavourable seasons, and its timing provides a powerful mechanism for synchronizing insect development. This book explores how seasonal signals are monitored and used by insects to enact specific molecular pathways that generate the diapause phenotype. The broad perspective offered here scales from the ecological to the molecular and thus provides a comprehensive view of this exciting and vibrant research field, offering insights on topics ranging from pest management, evolution, speciation, climate change and disease transmission, to human health, as well as analogies with other forms of invertebrate dormancy and mammalian hibernation.