By Jamie Martin
A recent study from Michigan State University reveals that overplanting Bt corn in areas with low corn rootworm risk is causing the pest to grow more resistant.
Bt corn is genetically modified to produce toxins that kill pests like the corn rootworm, one of the most damaging crop pests in the U.S.
The study found that eastern Corn Belt states — including Ohio, Michigan, and Pennsylvania — are planting high levels of Bt corn despite low rootworm pressure. This unnecessary use is speeding up resistance among pests and driving up seed costs.
“Field corn is plagued by the corn rootworm, which is one of the toughest, most amazing pests that exists. I like to think of the corn rootworm as ‘Loki’ because it’s a trickster — it just keeps evolving resistance to everything we throw at it,” said Professor Felicia Wu from MSU.
Wu’s team estimates that reducing Bt corn planting in low-risk states from 50% to 18% could save $99 million annually and nearly $2 billion over time. The study encourages offering farmers more seed choices and educating them about targeted planting.
The root of the issue is natural selection. Overexposing pests to toxins — even when they aren’t a threat — speeds up resistance, making valuable technology less effective where it’s truly needed.
The study, published in science and partly funded by the USDA, calls for smarter Bt corn use to preserve its benefits for the future.
Photo Credit: michigan-state-university-msu
Categories: National