ABSTRACT
World crop losses to pests are estimated to be about 35%. Mammal and bird losses appear to be more severe in the tropics and subtropics than in the temperate region, but these losses are low compared with losses to the three major pest groups of insects, pathogens, and weeds. In addition to the 35% preharvest loss an estimated 20% postharvest loss results from another group of pests, primarily microorganisms, insects, and rodents. Although pesticides are often considered to be the most important control technology for pests, biological and cultural controls in fact are more important than pesticides when a comparison is based on managed acres. The Hessian fly, a serious pest of wheat, is effectively controlled on at least a third of Hessian fly infested acreage by Hessian fly resistant varieties. Corn rootworms are controlled successfully in about 60% of US corn acreage by employing crop rotations.
