The study of parasitoid communities has direct relevance to general ecological theory and to the applied practice of biological control. Yet, despite the existence of a large and active international research community involved in the study of parasitoids, until now no books devoted to the theme of parasitoid community ecology have been available. Here, with a healthy mix of general discussions and specific examples such as tortricids and weevils, the authors constructively review and evaluate our understanding of these often very complex systems. The book emphasizes basic science, linking the discussion to wider areas such as population dynamics, food webs, competition, and community structure. The more applied end of the subject is covered in a section exclusively devoted to biological control. This book, the first to deal entirely with ecological aspects of parasitoid biology, offers summaries of the state of the field by leading researchers and identifies critical areas in need of further investigation. Students, researchers, and teachers in the field of ecology, animal behavior, entomology, forestry, and agriculture will all want to have a copy of the book on their shelves.
Insect parasitoids are a fascinating group of animals in many respects. Perhaps the most fascinating point is that these insects, in the course of the evolutionary time, have developed an impressive way to use chemical compounds to dialogue with the different protagonists of their environment (i.e., conspecifics, their hosts and the plants on which their hosts are living). Unravelling the evolutionary meaning of such chemical communication networks can give new insights into the ecology of these insects and especially on how to improve their use for the control of noxious pests in biological control programmes. Chemical Ecology of Insect Parasitoids is a timely publication, with organised chapters to present the most important knowledge and discoveries that have taken place over the last decade, and their potential use in pest control strategy. Specific relevant case studies are presented to enhance the reader's experience. Suited to graduate students and professional researchers and practitioners in pest management, entomology, evolutionary biology, behavioural ecology, and chemical ecology, this book is essential for anyone needing information on this important group of insects.
Most insect parasitoids are related to two insect orders, Diptera and Hymenoptera, some having a specific host while others have a vast host range. As such, the opening chapter of Parasitoids: Biology, Behavior and Ecology discusses the influence of host preference and host specificity in biological control programs and their role in different biological control methods.The behavioral responses of parasitoids can determine the efficiency of a parasitoid species to control host pests. The functional response is one of the most important behavioral responses. The authors show that type II functional response is more common than the other types (I, III, IV and V) of functional response for most parasitoid species. In some research, type III functional response was also reported for parasitoids.The closing study hypothesized that conditioned parasitoids will parasitize more target hosts compared with individuals without prior conditioning. In conditioning experiments, females of the wasp Trichogramma cacoeciae, a generalist egg parasitoid, oviposited in Lobesia botrana eggs while exposed to L. botrana's synthetic sex pheromone. Contrary to the hypothesis, this treatment failed to increase the parasitism rate in a subsequent exposure to the conditioned olfactory cue.
Parasitoids lay their eggs on or in the bodies of other species of insect, and the parasitoid larvae develop by feeding on the host, causing its eventual death. Known for a long time to applied biologists for their importance in regulating the population densities of economic pests, parasitoids have recently proven to be valuable tools in testing many aspects of evolutionary theory. This book synthesizes the work of both schools of parasitoid biology and asks how a consideration of evolutionary biology can help us understand the behavior, ecology, and diversity of the approximately one to two million species of parasitoid found on earth. After a general introduction to parasitoid natural history and taxonomy, the first part of the book treats the different components of the reproductive strategy of parasitoids: searching for a host, host selection, clutch size, and the sex ratio. Subsequent chapters discuss pathogens and non-Mendelian genetic elements that affect sexual reproduction; evolutionary aspects of the physiological interactions between parasitoid and host; mating strategies; life history theory and community ecology. A special effort is made to discuss the theoretical background to the subject, but without the use of mathematics.
How is the staggering biodiversity of the parasitoid insects maintained? This book, first published in 1994, explores patterns in host-parasitoid interactions, including parasitoid community richness, the importance of parasitoids as mortality factors, and their impact on host densities as determined by the outcomes of parasitoid introductions for biological control. It documents general patterns using data sets generated from the global literature and evaluates potential underlying biological, ecological and evolutionary mechanisms. A theme running throughout the book is the importance of host refuges as a major constraint on host-parasitoid interactions. Much can be learnt from the analysis of broad patterns; a few simple rules can go a long way in explaining the major components of these interactions. This book will be an invaluable resource for researchers interested in community ecology, population biology, entomology and biological control.
One hundred years after Darwin considered how sexual selection shapes the behavioral and morphological characteristics of males for acquiring mates, Parker realized that sexual selection continues after mating through sperm competition. Because females often mate with multiple males before producing offspring, selection favors adaptations that allow males to preempt sperm from previous males and to prevent their own sperm from preemption by future males. Since the 1970s, this area of research has seen exponential growth, and biologists now recognize sperm competition as an evolutionary force that drives such adaptations as mate guarding, genital morphology, and ejaculate chemistry across all animal taxa. The insects have been critical to this research, and they still offer the greatest potential to reveal fully the evolutionary consequences of sperm competition. This book analyzes and extends thirty years of theoretical and empirical work on insect sperm competition. It considers both male and female interests in sperm utilization and the sexual conflict that can arise when these differ. It covers the mechanics of sperm transfer and utilization, morphology, physiology, and behavior. Sperm competition is shown to have dramatic effects on adaptation in the context of reproduction as well as far-reaching ramifications on life-history evolution and speciation. Written by a top researcher in the field, this comprehensive, up-to-date review of the evolutionary causes and consequences of sperm competition in the insects will prove an invaluable reference for students and established researchers in behavioral ecology and evolutionary biology.
The Ichneumonoidea is a vast and important superfamily of parasitic wasps, with some 60,000 described species and estimated numbers far higher, especially for small-bodied tropical taxa. The superfamily comprises two cosmopolitan families - Braconidae and Ichneumonidae - that have largely attracted separate groups of researchers, and this, to a considerable extent, has meant that understanding of their adaptive features has often been considered in isolation. This book considers both families, highlighting similarities and differences in their adaptations. The classification of the whole of the Ichneumonoidea, along with most other insect orders, has been plagued by typology whereby undue importance has been attributed to particular characters in defining groups. Typology is a common disease of traditional taxonomy such that, until recently, quite a lot of taxa have been associated with the wrong higher clades. The sheer size of the group, and until the last 30 or so years, lack of accessible identification materials, has been a further impediment to research on all but a handful of ‘lab rat’ species usually cultured initially because of their potential in biological control. New evidence, largely in the form of molecular data, have shown that many morphological, behavioural, physiological and anatomical characters associated with basic life history features, specifically whether wasps are ecto- or endoparasitic, or idiobiont or koinobiont, can be grossly misleading in terms of the phylogeny they suggest. This book shows how, with better supported phylogenetic hypotheses entomologists can understand far more about the ways natural selection is acting upon them. This new book also focuses on this superfamily with which the author has great familiarity and provides a detailed coverage of each subfamily, emphasising anatomy, taxonomy and systematics, biology, as well as pointing out the importance and research potential of each group. Fossil taxa are included and it also has sections on biogeography, global species richness, culturing and rearing and preparing specimens for taxonomic study. The book highlights areas where research might be particularly rewarding and suggests systems/groups that need investigation. The author provides a large compendium of references to original research on each group. This book is an essential workmate for all postgraduates and researchers working on ichneumonoid or other parasitic wasps worldwide. It will stand as a reference book for a good number of years, and while rapid advances in various fields such as genomics and host physiological interactions will lead to new information, as an overall synthesis of the current state it will stay relevant for a long time.
The multitrophic level approach to ecology addresses the complexity of food webs much more realistically than the traditional focus on simple systems and interactions. Only in the last few decades have ecologists become interested in the nature of more complex systems including tritrophic interactions between plants, herbivores and natural enemies. Plants may directly influence the behaviour of their herbivores' natural enemies, ecological interactions between two species are often indirectly mediated by a third species, landscape structure directly affects local tritrophic interactions and below-ground food webs are vital to above-ground organisms. The relative importance of top-down effects (control by predators) and bottom-up effects (control by resources) must also be determined. These interactions are explored in this exciting volume by expert researchers from a variety of ecological fields. This book provides a much-needed synthesis of multitrophic level interactions and serves as a guide for future research for ecologists of all descriptions.
