Parasites that manipulate the behaviour of their hosts represent striking examples of adaptation by natural selection. This text provides an authoritative review of host manipulation by parasites that assesses developments in the field and lays out a framework for future research.

When Nancy Beckage and I first met in Lynn Riddiford's laboratory at the University of Washington in the mid 1970s, the fields of parasitology, behavior, and endocrinology were thriving and far-flung--disciplines in no serious danger of intersecting. There were rumors that they might have some common ground: Behavioural Aspects of Parasite Transmission (Canning and Wright, 1972) had just emerged, with exciting news not only of the way parasites themselves behave, but also of Machiavellian worms that caused intermediate hosts to shift fundamental responses to light and disturbance, becoming in the process more vulnerable to predation by the next host (Holmes and Bethel, 1972). Meanwhile, biologists such as Miriam Rothschild (see Dedication), G. B. Solomon (1969), and Lynn Riddiford herself (1975) had suggested that the endocrinological rami of parasitism might be subtle and pervasive. In general, however, para fications sites were viewed as aberrant organisms, perhaps good for a few just-so stories prior to turning our attention once again to real animals. In the decade that followed, Pauline Lawrence (1986a,b), Davy Jones (Jones et al. , 1986), Nancy Beckage (Beckage, 1985; Beckage and Templeton, 1986), and others, including many in this volume, left no doubt that the host-parasite combination in insect systems was physiologically distinct from its unparasitized counterpart in ways that went beyond gross pathology.

When a parasite invades an ant, does the ant behave like other ants? Maybe not-and if it doesn't, who, if anyone, benefits from the altered behaviors? The parasite? The ant? Parasites and the Behavior of Animals shows that parasite-induced behavioral alterations are more common than we might realize, and it places these alterations in an evolutionary and ecological context. Emphasizing eukaryotic parasites, the book examines the adaptive nature of behavioral changes associated with parasitism, exploring the effects of these changes on parasite transmission, parasite avoidance, and the fitness of both host and parasite. The behavioral changes and their effects are not always straightforward. To the extent that virulence, for instance, is linked to parasite transmission, the evolutionary interests of parasite and host will diverge, and the current winner of the contest to maximize reproductive rates may not be clear, or, for that matter, inevitable. Nonetheless, by affecting susceptibility, host/parasite lifespan and fecundity, and transmission itself, host behavior influences parameters that are basic to our comprehension of how parasites invade host populations, and fundamentally, how parasites evolve. Such an understanding is important for a wide range of scientists, from ecologists and parasitologists to evolutionary, conservation and behavioral biologists: The behavioral alterations that parasites induce can subtly and profoundly affect the distribution and abundance of animals.

It is clear that many fascinating problems still remain to be addressed in parasite transmission modelling, from better understanding of transmission processes and natural history of infection to investigating the impact of ecological and spatial scales, climate change, host immunity and social behaviour, parasite-host evolutionary dynamics and parasite community ecology on parasite transmission. This book captures some of the advances made in recent years and provides indications of ways forward for addressing these questions by shedding light on developments in conceptual frameworks and modelling tools as well as the emergence of new data forms for aiding model construction, testing and analysis. Another important advance has been the parallel development of robust computationally-intensive statistical methods to allow model testing and parameterization by aiding the fitting of models to complex data. This is an exciting area of work, which we believe will broaden the scope of mathematical modelling in investigating parasite transmission processes. In particular, we expect this advance will now allow modellers to begin the successful development and analysis of mechanistically-rich models of parasite transmission that will facilitate better integration of the variety of mechanisms increasingly recognized as important in simultaneously affecting transmission, including abiotic processes, trophic and evolutionary interactions, movement in space, and behaviour and even physiology of the individual. We foresee a continuing bright future for using mathematical modelling to clarify parasite transmission dynamics and address problems related to effective parasite control. Ultimately, through this improved application of models to research and management, we expect that parasite control would be an achievable goal bringing benefits to a vast number of our fellow human beings.

This edited volume focuses on parasite-host relationships and the behavioral changes parasites may trigger in their hosts. Parasites have developed strategies which enhance their chances to find a host to survive inside its body and to become most easily transmitted to one another. Many of these parasites influence the host’s behavior by various mechanisms, so that the rate of their transmissions to further hosts becomes considerably enhanced in comparison to that of non-influenced specimens of the same host species. A broad number of recent studies elucidate more and more examples in an extreme spectrum of host-parasite relationships, where successful transmission and /or survival of a parasite inside a host is based on parasite-derived behavioral manipulations of the hosts. In the literature, an increasing numbers of papers appear which prove that these behavioral alterations are based on complicated psychoimmunologic, neuropharmacologic and genomically steered mechanisms. Researchers working in parasitology or behavioral sciences will find this work thought-provoking, instructive and informative.

Blood-sucking insects are the vectors of many of the most debilitating parasites of man and his domesticated animals. In addition they are of considerable direct cost to the agricultural industry through losses in milk and meat yields, and through damage to hides and wool, etc. So, not surprisingly, many books of medical and veterinary entomology have been written. Most of these texts are organized taxonomically giving the details of the life-cycles, bionomics, relationship to disease and economic importance of each of the insect groups in turn. I have taken a different approach. This book is topic led and aims to discuss the biological themes which are common in the lives of blood-sucking insects. To do this I have concentrated on those aspects of the biology of these fascinating insects which have been clearly modified in some way to suit the blood-sucking habit. For example, I have discussed feeding and digestion in some detail because feeding on blood presents insects with special problems, but I have not discussed respiration because it is not affected in any particular way by haematophagy. Naturally there is a subjective element in the choice of topics for discussion and the weight given to each. I hope that I have not let my enthusiasm for particular subjects get the better of me on too many occasions and that the subject material achieves an overall balance.

In addition, the author develops new insights, especially in his examination of the intricate relationships between parasites and their social hosts through the rigorous use of evolutionary and ecological concepts.".

This book develops and tests an ecological and evolutionary theory of the causes of human values—the core beliefs that guide people’s cognition and behavior—and their variation across time and space around the world. We call this theory the parasite-stress theory of values or the parasite-stress theory of sociality. The evidence we present in our book indicates that both a wide span of human affairs and major aspects of human cultural diversity can be understood in light of variable parasite (infectious disease) stress and the range of value systems evoked by variable parasite stress. The same evidence supports the hypothesis that people have psychological adaptations that function to adopt values dependent upon local infectious-disease adversity. The authors have identified key variables, variation in infectious disease adversity and in the core values it evokes, for understanding these topics and in novel and encompassing ways. Although the human species is the focus in the book, evidence presented in the book shows that the parasite-stress theory of sociality informs other topics in ecology and evolutionary biology such as variable family organization and speciation processes and biological diversity in general in non-human animals.

Parasites and infectious diseases are everywhere and represent some of the most potent forces shaping the natural world. They affect almost every aspect imaginable in the life of their hosts, even as far as the structure of entire ecosystems. Hosts, in turn, have evolved complex defences, with immune systems being among the most sophisticated processes known in nature. In response, parasites have again found ways to manipulate and exploit their hosts. Ever since life began, hosts and parasites have taken part in this relentless co-evolutionary struggle with far-reaching consequences for us all. Today, concepts borrowed from evolution, ecology, parasitology, and immunology have formed a new synthesis for the study of host-parasite interactions. Evolutionary parasitology builds on these established fields of scientific enquiry but also includes some of the most successful inter-disciplinary areas of modern biology such as evolutionary epidemiology and ecological immunology. The first edition of this innovative text quickly became the standard reference text for this new discipline. Since then, the field has progressed rapidly and an update is now required. This new edition has been thoroughly revised to provide a state-of-the-art overview, from the molecular bases to adaptive strategies and their ecological and evolutionary consequences. It includes completely new material on topics such as microbiota, evolutionary genomics, phylodynamics, within-host evolution, epidemiology, disease spaces, and emergent diseases. Evolutionary Parasitology is suitable for advanced undergraduates, graduate level students, and interdisciplinary researchers from a variety of fields including immunology, genetics, sexual selection, population ecology, behavioural ecology, epidemiology, and evolutionary biology. Those studying and working in adjacent fields such as conservation biology, virology, medicine, and public health will also find it an invaluable resource for connecting to the bases of their science.