Biological control involves discovering, importing, and using the most effective natural enemies of pest insects or weeds that can be found. More than 10 million natural enemies of many kinds are released each year by the University of California (UC) through its Biological Control divisions at Albany and Riverside.

Special close-up photography by Jack K. Clark, Visual Aids, UC Davis.

Sources of information and authorities consulted: Paul DeBach, Professor of Biological Control and Entomologist, University of California, Riverside; Richard L. Doutt, Professor of Entomology, Emeritus, Biological Control, Parlier; Richard L. Goeden, Associate Professor of Biological Control, UC, Riverside; Kenneth S. Hagen, Professor of Entomology, UC, Berkeley; Carl B. Huffaker, Professor of Entomology, UC, Berkeley; Charles E. Kennett, Specialist, Biological Control, UC, Berkeley; Robert van den Bosch, Professor of Entomology, UC, Berkeley; and the late James K. Holloway, U.S. Department of Agriculture entomologist. DeBach's Biological Control by Natural Enemies (Cambridge University Press, 1974) also provided valuable historical and statistical information.