What’s the deal with pest resistance?
Pests – insects, disease and weeds -- are a regular part of life. In homes and gardens, a heavy shoe or some hard pulling can stop weed pests, but this isn’t effective in a large crop field. For large areas, our pest removal practices have included spraying safe pesticides or relying on plant genetics to manage them. But many pests can reproduce quickly and often, allowing them to evolve and develop tolerance to some of our easiest, cheapest and most effective management tools. Some pests are completely tolerant to some pesticides. When this occurs, it is called pest resistance, because they can now resist and survive a specific management tactic that previously controlled them. Pest resistance is a natural process. . However, when it comes to something as valuable as our food and when there’s no easy way to fight a pest, it can lead to yield reductions and increasing costs. Farmers, landowners, scientists, private businesses, and groups of individuals are finding ways to preserve our management tools, prevent pest resistance, and develop management strategies for already resistant pests.
Examples of Resistant Weeds
Common cocklebur, common lambsquarters, common sunflower, giant foxtail, giant ragweed, horseweed, Kochia, Pennsylvania smartweed, waterhemp, and recently, Palmer amaranth.
Examples of Resistant Insects
Western corn rootworm (WCR), also soybean aphid populations near, but not yet inside, Iowa.
Examples of Resistant Diseases
Soybean cyst nematode (SCN) and frogeye leaf spot.