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The fruit fly Drosophila melanogaster is an established tool to study mechanisms of innate immunity. Drosophila flies and larvae launch elegant humoral and cellular innate immune responses against bacteria, viruses, fungi and parasites. The humoral immune response is based on microbial recognition primarily by peptidoglycan recognition proteins leading to the production of antimicrobial peptides (AMPs). In the past few decades, Drosophilists have dissected how flies react to systemic bacterial and fungal infections at the molecular level and shown how these mechanisms are conserved from human to man. Fly humoral immune response is mainly mediated by two evolutionarily conserved NF-κB signaling pathways, the Toll and the Immune deficiency (Imd) pathways. The discovery of the Toll receptor as a key regulator of immune response, first in cultured Drosophila cells and then in Drosophila in vivo, formed the basis of the Toll-Like Receptor (TLR) research in humans and mammals. More recently, this field has broadened considerably, including e.g. the antimicrobial responses taking place in the gut. Another interesting aspect related to innate immunity is the antiviral immune mechanisms found in Drosophila. Best understood are the mechanisms based on RNAi, primarily against RNA virus infections. More recently, the evolutionarily conserved molecule STING has been shown to integrate responses against both viruses and bacteria.

The comparative approach to immunology can be traced to the era of Pasteur and Metchnikov in which observations regarding foreign recognition in invertebrates was a factor in the develop ment of the principal concepts that created the foundation of what now is the broad field of immunology. With each major experimental and conceptual breakthrough, the classical, albeit essential, question has been asked "are the immune systems of phylogenetically primitive vertebrates and invertebrates similar to that of mammals?" Somewhat surprisingly for the jawed verte brates, the general answer has been a qualified form of "yes", whereas for agnathans and invertebrate phyla it has been "no" so far. The apparent abruptness in the appearance of the immune system of vertebrates is linked to the introduction of the somatic generation of the diversity of its antigen specific receptors. Therefore the questions regarding the origin and evolution of the specific immune system revolve around this phenomenon. With respect to the origin of the system (aside from the or igin of the rearranging machinery itself, the study of which is still in its infancy) one can ask questions about the cellular and mo lecular contexts in which the mechanism was introduced.

Both volumes of Parasites and Pathogens of Insects provide in-depth coverage of the interface between insect parasites and pathogens and hosts, and explore the relationships between these partners. They emphasize biochemical and molecular interactions, basic biology, and the roles of hormones, receptors, and other cellular components in modulating interactions between host insects and attacking agents. These topics also are assessed in relation to biotechnology and biological control. In the short term, these volumes fill a void in current literature by emphasizing basic interactions at the biochemical and molecular levels. In the long term, these interactions may provide avenues for exploitation to enhance the rate of "beneficial" parasitism or to reduce the rates of disease transmission and infection of vertebrate hosts. Presents the latest information on insect parasites and pathogens Describes biochemical and molecular host-parasite and host-pathogen relationships Covers mechanisms of insect pathogenicity and resistance Provides exceptional breadth of coverage and authoritative reviews Special topics Transposable elements in insect pathogens Co-evolution and gene transfer between hosts and invaders Biological control

Humans coexist with millions of harmless microorganisms, but emerging diseases, resistance to antibiotics, and the threat of bioterrorism are forcing scientists to look for new ways to confront the microbes that do pose a danger. This report identifies innovative approaches to the development of antimicrobial drugs and vaccines based on a greater understanding of how the human immune system interacts with both good and bad microbes. The report concludes that the development of a single superdrug to fight all infectious agents is unrealistic.

Insect Immunity, Volume 52 provides readers with the latest interdisciplinary reviews on the topic. It is an essential reference source for invertebrate physiologists, neurobiologists, entomologists, zoologists and insect chemists, providing invaluable chapters on Insect Antimicrobial Defenses: A Brief History, Recent Findings, Biases, and a Way Forward in Evolutionary Studies, Phagocytosis in Insect Immunity, The Melanization Response in Insect Immunity, Microbiota, Gut Physiology, and Insect Immunity, Intestinal Stem Cells: A Decade of Intensive Research in Drosophila and the Road Ahead, and Insect Symbiosis and Immunity: The Bean Bug-Burkholderia Interaction as a Case Study, along with other related topics.