Controlling pests without chemicals.

A survey examining the success of biological control of insects in agriculture concludes that this natural approach to pest containment is far more effective than often appreciated and should be more widely used. Several case studies explored by researchers at Oregon State University, Corvallis, found that biological pest control can solve problems effectively on a long-term basis and may yield a return on investment of 100-1,000% in the first year alone, after which the benefits go up in perpetuity.

"In these specific cases, we were surprised at the degree of success of biocontrol, how widespread and quickly it worked, how cost-effective it was," indicates M.T. AliNiazee, professor of entomology. Based on this, there's no doubt in my mind that biocontrol should be more heavily exploited."

In an agricultural world riddled with insect pests, biological control most often is the use of an insect parasitoid, predator, or pathogen to eliminate the damaging pest. Other tools like pheromones and trapping are possibilities as well. Utilizing this approach, AliNiazee points out, does not suggest that chemical pest control is ruled out entirely. Lower amounts of chemicals, or careful timing of their use, can be combined with biological control and other agricultural tools in a concept called "integrated pest management" (IPM).

Biocontrol has found some of its greatest success in perennial crops, including fruits and nuts. There probably are great opportunities in larger mainstream crops such as cotton, corn, soybeans. and potatoes, he maintains. "There are some clear advantages that make biological control socially desirable. It can reduce harm to the environment, improve health and safety of food products, even lower consumer costs."

In the early 1900s, before a huge agro-chemical industry developed, there was considerable interest in biological control, Aliniazee notes. With increasing consumer skepticism about chemicals and the growth of insect resistance to pesticides, attitudes may have come full circle. "It's still hard to break the agricultural dependence on chemicals because it provides that insurance that most growers would rather have....

"There's a lot more that could be done, but we have to confront the chemical-dependent mentality. For instance, cotton farmers use extensive sprays to control pests such as the boll weevil and boll worm, but in the process create several new problems by killing beneficial insects." Breaking that cycle with different chemical regimens, protection of useful insect predators, and other tools of IPM radically is reducing pesticide use in that crop in some regions. "Oregon, California, and Hawaii have been very progressive in encouraging biological control.... However, there's a lot more work to do throughout this country and the world as a whole."