This book concentrates on invasive arthropods damaging to agriculture, although relevant examples and discussions with other organisms and situations are included. Some socio-political facets are considered in overviews of plant health protection programs, including the origins of regulatory plant health in the United States, environmental and economic costs of alien arthropods, and international standards and avenues for sharing information about pests. Risk assessment is a vital scientific component of efforts to thwart the negative effects of invasive species, and some chapters deal with pathways of introduction, predicting the invasive potential of arthropods, and forecasting the likely geographic distribution of exotic insects. New eradication, control and quarantine treatment methods have been developed for use in programs against invasive species, and these are addressed in a series of chapters. Biological control has been at the nexus of the invasive species debate because the benefits sought after through the deliberate introduction of beneficial organisms may have unintended and undesirable negative effects. Accordingly, chapters are devoted to these topics.