The new millennium has seen a major paradigm shift in insect endocrinology. Great advancements are being made which establish that nutrition and growth play a central role in diverse cellular and physiological phenomena during insect development and reproduction. Nutrition affects rates of growth and is mainly regulated by the function of the pathway of insulin/insulin-like growth factor signalling. This pathway is highly conserved across species and ultimately regulates rates of cell growth and proliferation in growing organs. Insulin and insulin-like peptides (ILPs) are some of the best studied hormones in the animal kingdom and all share a common structural motif and initiate a wide range of closely similar physiological processes in higher organisms. In insects, nutrition, via circulating sugar, promotes release of ILPs from brain neurosecretory cells into the haemolymph, which act on peripheral tissues and stimulate protein synthesis and cell growth. Therefore, insect ILPs are common mediators between nutrition and growth in insects and are functionally analogous to mammalian insulin. The 1980s and 1990s witnessed great progress in elucidation of the physiological and molecular mechanism of action of numerous insect hormones involved in regulation of growth, development, reproduction and metabolism. But the signals for the initiation or termination of controlled events remained largely unknown. ILPs were first identified from the silkmoth Bombyx mori and were named bombyxins, but related peptides were soon found in numerous species and their functions elucidated. The insulin signalling pathway is now recognized as a central factor in the timing of cell proliferation, growth, longevity, reproduction, and reproductive diapause, as well as social behaviour. Recent work has revealed that the insulin signalling pathway is closely integrated with that of various other hormones, including ecdysteroids, the juvenile hormones and neuropeptide(s) such a prothoracicotropic hormone. In addition, the pathway is also linked with both circadian (daily) and photoperiodic (seasonal) clocks potentially providing a basis for its timing function. This Research Topic aims to provide the only current collection of recent advances on insect ILPs. We encouraged submissions on all areas related to identification, characterization, regulation and physiological functions of insect ILPs. We welcomed both full and short reviews and original research articles.

Physiological Systems in Insects discusses the roles of molecular biology, neuroendocrinology, biochemistry, and genetics in our understanding of insects. All chapters in the new edition are updated, with major revisions to those covering swiftly evolving areas like endocrine, developmental, behavioral, and nervous systems. The new edition includes the latest details from the literature on hormone receptors, behavioral genetics, insect genomics, neural integration, and much more. Organized according to insect physiological functions, this book is fully updated with the latest and foundational research that has influenced understanding of the patterns and processes of insects and is a valuable addition to the collection of any researcher or student working with insects. There are about 10 quintillion insects in the world divided into more than one million known species, and some scientists believe there may be more than 30 million species. As the largest living group on earth, insects can provide us with insight into adaptation, evolution, and survival. The internationally respected third edition of Marc Klowden's standard reference for entomologists and researchers and textbook for insect physiology courses provides the most comprehensive analysis of the systems that make insects important contributors to our environment. Third edition has been updated with new information in almost every chapter and new figures Includes an extensive up-to-date bibliography in each chapter Provides a glossary of common entomological and physiological terms

Hormones, Brain and Behavior, Third Edition offers a state-of-the-art overview of hormonally-mediated behaviors, including an extensive discussion of the effects of hormones on insects, fish, amphibians, birds, rodents, and humans. Entries have been carefully designed to provide a valuable source of information for students and researchers in neuroendocrinology and those working in related areas, such as biology, psychology, psychiatry, and neurology. This third edition has been substantially restructured to include both foundational information and recent developments in the field. Continuing the emphasis on interdisciplinary research and practical applications, the book includes articles aligned in five main subject sections, with new chapters included on genetic and genomic techniques and clinical investigations. This reference provides unique treatment of all major vertebrate and invertebrate model systems with excellent opportunities for relating behavior to molecular genetics. The topics cover an unusual breadth (from molecules to ecophysiology), ranging from basic science to clinical research, making this reference of interest to a broad range of scientists in a variety of fields. Comprehensive and updated coverage of a rapidly growing field of research Unique treatment of all major vertebrate and invertebrate model systems with excellent opportunities for relating behavior to molecular genetics Covers an unusual breadth of topics and subject fields, ranging from molecules to ecophysiology, and from basic science to clinical research Ideal resource for interdisciplinary learning and understanding in the fields of hormones and behavior

Intraspecific communication involves the activation of chemoreceptors and subsequent activation of different central areas that coordinate the responses of the entire organism—ranging from behavioral modification to modulation of hormones release. Animals emit intraspecific chemical signals, often referred to as pheromones, to advertise their presence to members of the same species and to regulate interactions aimed at establishing and regulating social and reproductive bonds. In the last two decades, scientists have developed a greater understanding of the neural processing of these chemical signals. Neurobiology of Chemical Communication explores the role of the chemical senses in mediating intraspecific communication. Providing an up-to-date outline of the most recent advances in the field, it presents data from laboratory and wild species, ranging from invertebrates to vertebrates, from insects to humans. The book examines the structure, anatomy, electrophysiology, and molecular biology of pheromones. It discusses how chemical signals work on different mammalian and non-mammalian species and includes chapters on insects, Drosophila, honey bees, amphibians, mice, tigers, and cattle. It also explores the controversial topic of human pheromones. An essential reference for students and researchers in the field of pheromones, this is also an ideal resource for those working on behavioral phenotyping of animal models and persons interested in the biology/ecology of wild and domestic species.

Insects are by far the most diverse and abundant animal group with respect to the number of species globally, in ecological habitats and in biomass. The ecological and evolutionary success of insects depends in part on their countless relationships with beneficial microorganisms, which are known to influence all aspects of their physiology, ecology, and evolution. These symbiotic associations are known to: (a) enhance nutrient-poor diets, (b) aid digestion of recalcitrant food components, (c) protect from predators, parasites, and pathogens, (d) contribute to inter- and intraspecific communication, (e) affect efficiency as disease vectors and (f) govern mating and reproductive systems. Characterization, exploitation, and management of the insect-bacterial symbiotic associations can contribute significantly to the control of agricultural pests and disease vectors. Insects that depend exclusively on nutritionally restricted diets such as plant sap, vertebrate blood, and woody material, commonly possess obligate mutualistic endosymbionts involved in the provision of essential nutrients or in the degradation of food materials. These intracellular mutualists commonly have the following biological features: (a) they localize inside bacteriocytes, (b) are essential for fitness, (c) are maternally transmitted, and (d) display strict host-symbiont co-evolutionary patterns. In addition to obligate endosymbionts, many insects harbor bacteria that are not essential for their survival or fecundity and are typically maintained with a patchy distribution in host populations. Such symbionts can induce reproductive phenotypes in insect hosts, including male-killing, feminization, parthenogenesis or cytoplasmic incompatibility. Because these bacteria manipulate their host’s reproductive biology, they also likely accelerate host processes. As for essentially all animals, microbial communities are particularly prominent in the digestive tract, where they may be key mediators of the varied lifestyles of insect hosts. The contribution of microorganisms, particularly gut microorganisms, to insect function is highly relevant from several perspectives, linking to applications in medicine, agriculture, and ecology. Gut-associated microorganisms can include protists, fungi, archaea, and bacteria, but it is generally accepted that bacterial species dominate the microbial community in the guts of most insects. Gut-associated bacteria can influence: (a) vectoring efficiency, (b) developmental time, (c) decomposition of plant biomass and carbon cycle, (d) nitrogen fixation and nitrogen cycle, (e) mating incompatibilities, and (f) detoxification of pesticides leading to the acquisition of insecticide resistance.

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.

The human genome encompasses ˜ 860 G protein-coupled receptors (GPCRs) including 374 non-chemosensory GPCRs. Half of these latter GPCRs recognize (neuro)peptides as natural ligands. GPCRs thus play a pivotal role in neuroendocrine communication. In particular, GPCRs are involved in the neuroendocrine control of feeding behavior, reproduction, growth, hydromineral homeostasis and stress response. GPCRs are also major drug targets and hence possess a strong potential for the development of innovative pharmaceuticals. The aim of this Research Topic was to assemble a series of review articles and original research papers on neuropeptide GPCRs and their ligands that would illustrate the different facets of the studies currently conducted in this domain.