There is growing interest in the exploitation of naturally occurring micro organisms for the control of crop pests, weeds, and diseases. Biological control agents (BCAs) may offer more environmentally friendly alternatives to chemical pesticides. They could also be used where pests have developed resistance to con ventional pesticides. Unfortunately, there is comparatively little investment in the research and development of these organisms compared with that spent on the discovery of chemical pesticides. Two reasons for this are that microbial pesticides usually have a narrow host range, and that they often give inconsistent and poor control in field trials. Consequently, more attention is being given to the selection of broad-spectrum biopesticides and improvements in production, formulation, and application technologies. Efforts are also being made to optimize the impact of these agents by integrating them with other novel crop protection strategies (1).