Recent interest in nonchemical methods of pest control has brought renewed attention to the biological control of plant pests in the fields of entomology, plant pathology, and weed science. Ecological Interactions and Biological Control addresses issues of theory and practice common to all three fields. Focusing on systems rather than on individual problems, the contributors are able to look at the larger issues of how ecological theory has aided biological control and vice versa. Most important, they suggest ways to integrate theory and practice more closely in order to contribute to the future development of biological control.