The best alternative to chemical control is often seen as being biological control - the introduction of natural enemies in areas where foreign pests become abundant. However, biological control alone is not always sufficient to maintain pest populations under a tolerable level; and it is necessary to learn how to make it compatible with other methods of control, and in particular with chemicals, in integrated control programs. Data on these important aspects was collected and elaborated over a period of seven to eight years and synthesized in this volume, which was originally published in...