ABSTRACT
Biological control of pests has been actively practiced for more than 100 years, and it has had some 150 spectacular successes, which in economic terms have been just as impressive as in ecological terms. However, the obtained successes are only the tip of the iceberg of all the work carried out in the field. A major ecological and economic challenge is to improve the ratio of successes in biological control, while retaining the excellent safety record of this approach to pest control.
