Pest control strategies must be cost-effective as well as effective, easy to implement, and readily integrated with other crop-production practices. Economic factors involving cost-effectiveness include crop prices, costs and availability of labor, land, equipment, and other production inputs.
Pest-management programs must ensure that pests in the agroecosystem can be managed over the long-term without adverse environmental, economic, or safety consequences. Current pest-management strategies that rely on repeated applications of conventional broad-spectrum pesticides encourage the development of resistant species. In new ecologically based approaches, addressing potential development of pest resistance will be important.
EBPM promotes the economic and environmental viability of agriculture by using knowledge of interactions between crops, pests, and naturally occurring pest-control organisms to modify cropping systems in ways that reduce damage associated with pests. Ecologically based management relies on a comprehensive knowledge of the ecosystem, including the natural biological interactions that suppress pest populations. It is based on the recognition that many conventional agricultural practices disrupt natural processes that suppress pests. Agricultural practices recommended by EBPM will augment natural processes, supplemented by biological-control organisms and products, resistant plants, and targeted pesticides.
An ecosystem is dynamic with interacting physical, chemical, and biological processes. The coexisting crops, herbivores, predators, pathogens, weeds, and other organisms interact with one another and respond to their environment. Each organism has developed a repertoire of offensive and defensive maneuvers in response to changes in the behavior of other organisms in the cropping system. This web of interrelated interactions also confers stability on the system; while a population increases and decreases, it is subject to the checks and balances imposed by populations of the other organisms.
Stability (i.e., low variance in density of pests over time) is an essential feature of successful pest management. When effective predators, parasites, pathogens, or competitors of potentially destructive pests are present in the managed ecosystem, pest populations are suppressed and held in check. In natural systems, biological-control organisms are often quite diverse, leading to stable, low pest populations.
Activity of most biological organisms is density dependent—i.e., when pest density is low, density of, and hence suppressive activity of control organisms tends to be low, and vice versa. Negative feedback related to population density keeps both pest and control organism from both glut and extinction. Because neither pesticides nor host-plant resistance methods are responsive to feedback, achieving stability and balance within the agroecosystem is not possible with those systems, but is a fundamental goal of EBPM. EBPM is founded on the importance of natural processes inherent within agricultural and forest produc-