Starting in the 1950s, most growers began to rely on agrochemical-based strategies to manage pests. Low-cost pesticides were seen as convenient “silver bullet” solutions, but that view is changing. Repeated use of pesticides has brought about resistance in many pest species. In addition, broad-spectrum insecticides not only kill crop pests but also important non-target predators and pollinators. These disruptions lead to pests resurging and returning to crops faster and in greater numbers, but with fewer predators and parasitoids to control them. In time, the repeated use of pesticides can create conditions where pests thrive, resulting in growers who feel compelled to lean more heavily on the same agrichemical controls that caused the problem; this situation has been named the “pesticide treadmill.” 

Interseeding
Seeding a cover crop into corn in a no-till system. This is an example of how more farmers are taking advantage of holistic, ecological principles to manage pests, nutrients and water with fewer purchased inputs. Photo by Edwin Remsberg

More and more farmers are becoming aware of these risks to their operations, human health and the environment, and are turning instead to ecological pest management strategies for solutions. Ecological strategies treat the farm like an agroecosystem, meaning they use good agricultural practices that mimic and reinforce the natural relationships already built into farming systems. Using cover crops instead of leaving the soil bare, for example, protects soil from erosion, shades out weeds, nurtures soil microbiology and attracts beneficial arthropods that eat pests, pollinate crops and recycle crop debris. In this way, good agricultural practices boost the natural defenses of your farm.

Polistes Wasp
A paper wasp with cabbageworm prey in broccoli. Photo by Russ Ottens, University of Georgia

These good agricultural practices, however, require careful farm planning and habitat management, and they depend on two driving ecological concepts: biodiversity and biological control. Biodiversity refers to all of the living species found in and around the farm, including crop plants, weeds, livestock, woody plants and shrubs, arthropods, soil biology, wildlife and many other organisms. The interactions between these organisms and their environment provide valuable ecosystem services like biological control, or the use of natural enemies to reduce, prevent and delay pest outbreaks. Instead of reacting to pest problems with off-farm inputs, ecological strategies prevent problems from arising by proactively addressing their root causes, such as low biodiversity, stressed crops and degraded soils.