(And What You Can Do About It)

“Know your enemy,” the old adage says. Farmers know this intuitively, and well. From aphids to weevils, and everything in between, they’re acutely aware of just how devastating pests can be.

Fortunately, this isn’t just empty knowledge of a potential threat to be dreaded. In many cases, ag science has found ways to help control the damage these critters can inflict.

So, without further ado, here are the three most dangerous pests to American farmers, and some tips for helping make sure these enemies don’t get the best of your crop.

  1. Corn Rootworm

    By far the most significant cash crop in America is corn. Corn’s nemesis is the corn rootworm, inflicting a billion dollars of damage a year.

    It’s a devastating pest for a variety of reasons. It affects corn crops throughout the crop’s lifecycle, as larvae siphoning off nutrients at the roots and as adult insects feeding on foliage. It stays in fields where it’s settled. And it’s evolved a resistance to many traditional pesticides. That makes corn rootworm a feared presence.

    The best way to control Diabrotica (the scientific name of this pest) populations is using Bt-engineered corn. Using this bacterial form of pest control has protected corn from devastation. Rotating crops also helps, since the corn rootworm doesn’t like soybeans and other cash crops as much as its namesake. Conducting regular foliar sweeps to monitor and minimize impact is another deterrent method with proven success.

  2. Colorado Potato Beetle

    Fifty years, fifty different pesticides. That’s the shocking record of the Colorado potato beetle, which developed immunity to fifty different insecticides over the past five decades.

    As the name implies, this adaptable beetle prefers tubers, but will also chow down on tomatoes and eggplants. It eats everything–leaves, stems, roots. Left unchecked, it will take down fields at a time.

    Protecting your fields from this pesky insect takes strategy. Experts recommend using Bt strains to ward off larval infestation, changing up pesticides to erode these creatures’ tolerance, and timing control measures to target key points in the insect’s life cycle. 

  3. Stink Bugs

    They’re an annoyance in your home, but brown marmorated stink bugs (Halyomorpha halys) represent a serious hazard on the farm.

    Stink bugs are omnivorous pests who eat a highly varied diet of apples, pears, grapes, corn, and soybeans–and almost anything else it can get its mandibles on. Since their introduction from Asia, they’ve settled in 38 states.

    Maddeningly, they have a habit of eating corn from the inside out–which means damage is invisible until farmers remove the husks to find the kernels have already been eaten on otherwise healthy plants.

    Oh, and they’re tolerant of many pesticides. So there’s that.

    What to do about the stink bug? Experts suggest an integrated pest management (IPM) plan that doesn’t rely too heavily on chemical controls. If you are using pesticides, they recommend sequencing pyrethroids with carbamates. Scientists are developing more long-term strategies to deal with stink bugs.