Big-Picture Pest Management

Insecticides have historically been among the first tools we’ve reached for to save crops from insect damage, but integrated pest management experts stress that these should be considered only as a last line of defense. Fortunately, now more effective ways exist to wrangle insect pests and minimize the damage they can do.

- Susan M. Brackney

To see how these big-picture pest management practices all fit together, it helps to first understand why it’s time to step away from the spray. Turns out, when pesticides are used routinely over long periods of time, they actually give problem pests an advantage over the beneficial insects which prey upon them. That’s because insecticides kill indiscriminately, and it takes longer for some insect populations to bounce back.

“Herbivores typically grow much faster than predator insects,” says Jermaine Hinds, a technical review specialist with Sustainable Agriculture Research and Education Outreach. (SARE is a USDA-funded organization which is hosted by the College of Agriculture and Natural Resources at the University of Maryland.)

"Predator insects are larger and they require protein, so, it's harder to find food for them," he says. "Meanwhile, the populations of plant-eating insects can rebound from a toxic spray event much more quickly.

"Doing that over and over again, it's like you're pushing the beneficial insects further back and giving the pest species a humongous head start. The pesticides inadvertently help [insect pests] to develop faster and they often develop mutations to resist pesticides."

But there is at least one thing crop-eating insects can't easily get around. "Insects can't really develop resistance to avoiding all of the predators out there," Hinds says. That's why attracting more of those natural predators is key. By developing a more robust ecosystem on your farm or in the garden, you can draw a wider variety of beneficial insects in greater numbers and put them to work for you.

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