Nontarget Effects of Biological Control is the first book of its kind. The environmental safety of biological control has come under scrutiny due to several areas of concerns: the irreversibility of alien introductions, the prevalence of host switching to innocuous native or beneficial species, dispersal of the biocontrol agent to new habitats away from croplands, and the lack of research on the efficacy and impact of biocontrol attempts. The debate has been strongly polarized between conservationists and biological control practitioners. Nontarget Effects of Biological Control proposes that retrospective analyses of systems in place in which nontarget effects are now documented or suspected provide the necessary information for planning and evaluating future releases to reduce risk. The book presents case histories of past biological control introductions from island and continental ecosystems.