IMPORTANCE OF ECONOMIC INJURY LEVELS IN DEVELOPMENT OF INTEGRATED PEST CONTROL PROGRAMS

Although economic injury levels have long been considered of importance in determining the needs for pest control measures, they take on added significance in integrated pest control programs. The designation of damage tolerance levels defines the goals of the integrated control effort. These management goals should be defined in terms of damage not numbers of pests. Although insect numbers and damage incidence are related they are not perfectly correlated and the relationship varies with changes in the ecological and economic environment. Many plants have the ability to tolerate or compensate for large amounts of injury without affecting yield or quality. Other plants have a limited capacity to produce a marketable crop; pest injury which does not reduce the capacity of the plant is not damage. These characteristics of plants, among others, and the limitations of artificial control measures permit the maintenance of subeconomic levels of pests in agricultural crop areas. These subeconomic pest populations foster an entomophagous fauna. It is very difficult to calculate precise cost/potential benefit ratios because of subtile long-term effects of artificial controls and the vagaries of estimates of potential economic value of the harvested crop. © 1969 Dr. W. Junk N.V.