
Photo by Milo Inman, India
During my last post I mentioned this agricultural strategy in passing, and I’m actually fairly surprised that the topic hasn’t come up anywhere on the blog before. After all, IPM is an increasingly effective and interdisciplinary way to curb economic losses in crops around the world, and one that often attempts to reduce reliance on environmentally unfriendly chemicals like pesticides.
Completely eliminating an agricultural pest is not the ultimate goal of IPM. In fact, due to ecological intricacies and the risks of removing certain species from an ecosystem, merely lowering the number of pests to numbers that do not cause significant economic damage is more advisable. Achieving this reduction in pest populations “requires an understanding of the ecology of the cropping system, including that of the pests, their natural enemies, and the surrounding environment,” according to Professor Anthony Shelton of the Entomology Department at Cornell University. For example, knowing that a certain pest caterpillar species has certain predator species, a farmer might introduce some of the natural predators into his crop to prey on the harmful caterpillars. If the farmer also physically removes the caterpillars by hand and the pest population dwindles to zero, the natural predators might turn to a beneficial insect, like a pollinator, or even attack the crop itself. This is a very vague and hypothetical example but one that reflects the need to understand causes and effects in an ecosystem if one is planning to employ IPM effectively.
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