for the design of control programs; in extreme cases (as dis cussed below, by Fine et al. , this volume, and elsewhere) it can happen that immunization programs, although they protect vaccinated individuals, actually increase the overall incidence of a particular disease. The possibility that many nonhuman animal populations may be regulated by parasitic infections is another topic where it may be argued that conventional disciplinary boundaries have retarded investigation. While much ecological research has been devoted to exploring the extent to which competition or predator-prey interactions may regulate natural populations or set their patterns of geographical distribution, few substan tial studies have considered the possibility that infectious diseases may serve as regulatory agents (1,8). On the other hand, the many careful epidemiological studies of the trans mission and maintenance of parasitic infections in human and other animal populations usually assume the host population density to be set by other considerations, and not dynamically engaged with the disease (see, for example, (1,2)). With all these considerations in mind, the Dahlem Workshop from which this book derives aimed to weave strands together -- testing theoretical analysis against empirical facts and patterns, and identifying outstanding problems -- in pursuit of a better un derstanding of the overall population biology of parasitic in fections. For the purpose of the workshop, the term "parasite" was de fined widely to include viruses, bacteria, protozoans, fungi, and helminths.

Ecofriendly Pest Management for Food Security explores the broad range of opportunity and challenges afforded by Integrated Pest Management systems. The book focuses on the insect resistance that has developed as a result of pest control chemicals, and how new methods of environmentally complementary pest control can be used to suppress harmful organisms while protecting the soil, plants, and air around them. As the world's population continues its rapid increase, this book addresses the production of cereals, vegetables, fruits, and other foods and their subsequent demand increase. Traditional means of food crop production face proven limitations and increasing research is turning to alternative means of crop growth and protection. - Addresses environmentally focused pest control with specific attention to its role in food security and sustainability. - Includes a range of pest management methods, from natural enemies to biomolecules. - Written by experts with extensive real-world experience.