Nematodes that are parasites of insects are no longer a laboratory curiosity. They have begun to be accepted as environmentally benign alternatives to the use of chemical insecticides, for the control of insect pests. Nematode worms are now applied as biological control agents against insectpests of numerous horticultural and agricultural crops. This book provides a comprehensive review of entomopathogenic nematology. It begins by reviewing fundamental biology and setting a taxonomic foundation for nematodes and their bacterial symbionts. Several chapters are devoted to functionalprocesses involved in parasitism and to nematode ecology. Later chapters describe technological advances and control methodologies.