Biological control offers an ecologically sound and cost-effective method for eliminating weeds. Its use is rapidly expanding, both its range of use and the number of agents being development and released. The fourth edition of this catalogue provides a comprehensive reference source to all attempts at biological control of weeds undertaken through the end of 1996. The information is presented in four detailed lists: List A covers exotic vertebrates and fungi that have been released for biological control, and their target weeds. List B includes exotic invertebrates, essentially fish species, utilized to control weeds. List C covers organisms that have been deliberately manipulated for weed control within their natural ranges. List D covers organisms that have been released as biological control agents and now occur in countries other than those into which they were released. Each entry details the target weed, control agent, year of first release, country of origin of agent, status and degree of control, research organization involved, and key references. The book provides an invaluable means of keeping track of trends and developments throughout the world.