The Illusion of Integrated Pest Management

Article excerpt

Despite three decades of research, there is very little "I" in IPM. It's time to start over with an achievable goal.

In 1993, the U.S. Department of Agriculture (USDA), the Environmental Protection Agency (EPA), and the Food and Drug Administration (FDA) called for a national commitment to implement Integrated Pest Management (IPM) on 75 percent of U. S. crop acreage by the year 2000. The next year, USDA announced its IPM Initiative to embrace this commitment. Seven years have passed, and farm practices have changed very little. Indeed, the only significant change is that we know less than what we thought we knew about what IPM is. Revisiting what we mean by IPM will help us understand what went wrong with the initiative.

USDA and EPA struggled to come up with a workable definition of IPM and a suitable way to assess its level of adoption. This is not surprising, given the apparent confusion among policymakers as to what IPM is all about. The most recent attempt came in October 1998, when USDA announced that a given farm should have in place a management strategy for "prevention, avoidance, monitoring, and suppression" (PAMS) of pests. To qualify as IPM under these guidelines, a farmer must use tactics in at least three PAMS components. USDA defines "prevention" as the practice of keeping a pest population from ever infesting a crop. "Avoidance" may be practiced when pest populations exist in a field, but their impact on the crop can be avoided by some cultural practice. "Monitoring" refers to regular scouting of the crop to determine the need for suppressive actions. "Suppression" is used where prevention and avoidance have failed and will typically mean application of a chemical pesticide.

The major problem with the PAMS approach is that it does not recognize the concept of integration or compatibility among pest management tactics as envisioned by the founders of IPM. Simply mixing different management tactics does not constitute IPM. Mixing the tactics arbitrarily may actually aggravate pest problems or produce other unintended effects. For example, studies have documented antagonistic relationships between genetically resistant crop cultivars and biological control agents of insect pests. It is naive to assume that nonchemical or reduced-risk alternatives can be mixed and deployed in the same way in which pesticide "cocktails" have commonly been used in the past. Combining tactics to achieve the best long-term results requires considerable ecological finesse. Many potentially effective alternatives will provide only disappointment if they are used in the same way as conventional pesticides and are applied without good knowledge of how they affect other control agents.

A federal policy that promotes IPM without a proper understanding of IPM is doomed to failure. But just understanding IPM is not enough: Federal policy also must address how farmer adoption will be measured and provide incentives to encourage such adoption. This is not likely to happen in the foreseeable future. In view of this, we believe that the time has come for a major policy change at the federal level: Dispense with what has become an "IPM illusion" and shift the focus to a more definable goal, such as pesticide reduction (including risk reduction). Because policymakers in Washington seem to have a fuzzy view of the origin of IPM, we will begin with a brief historical account.

Historical perspective

Shortly after World War II, when synthetic organic insecticides became available, applied entomologists in California developed the concept of "supervised insect control." Entomologists in cotton-belt states such as Arkansas were advocating a similar approach. Under this scheme, insect control was "supervised" by qualified entomologists, and insecticide applications were based on conclusions reached from periodic monitoring of pest and natural-enemy populations. This was viewed as an alternative to calendar-based insecticide programs. …