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tles, ants, spiders, ground beetles, lacewings, pirate bugs, etc.), pollinators, and detritivores are also driven off the farm. And farms NEED these beneficial insects to function properly.
• Then the farmer comes back in the spring and plants entire fields of a single plant species, and guess who the first to arrive is? The pest. And there is no biotic resistance to the pest's

proliferation because all of the predators that keep those pests in check have been driven out of the system too. So the farmer sprays insecticides to replace the predation that Mother Nature normally gives for free, and further drives down the natural enemy communities, while temporarily suppressing the pests.
• An alternative is to provide habitat for natural enemy communities so that they are there when the pests arrive in the spring. And cover crops are a great way to do this!
• Research at the USDA-ARS laboratory in Brookings, SD has shown that cover crops preceding corn or soybean can have dramatic effects on natural enemy communities, sometimes increasing predator numbers by 10 times those found in insecticide-sprayed fields; these predators eat things like corn rootworms and soybean aphids.
• And these predators DO eat the pests: this research shows that cover crops preceding corn (and their associated predators) reduce the abundance of corn rootworms and the damage that they cause to corn plants. Now we are testing whether cover crops could be economically competitive with "traits-based management" (Bt corn, neonicotinoid seed treatments, etc.) on farms throughout the Plains region.
• But like any technology, cover crops need to be used correctly. Simply replacing one monoculture cash crop with a monoculture cover crop has been shown to foster pest populations like pea weevils and armyworms. The science is still rolling in, but it seems that diversifying the cover crop mix to include several plant species may