Corn rootworms have developed resistance to Bt traits, particularly in continuous corn, making control more difficult. While crop rotation and conventional insecticides can help, resistance to some products has already developed. Two potential solutions are emerging. One involves genetic modification to make resistant insects susceptible again, while the other explores biological products.

Researchers at the University of California San Diego successfully used gene editing to make pesticide-resistant fruit flies 100% susceptible, removing resistant genes and replacing them with ones that make the insects vulnerable to pesticides. While this is promising, Erin Hodgson, a professor at Iowa State University, notes that applying this at a field scale is complex and may take time.

In addition to genetic approaches, bioinsecticides like TS201 from NewLeaf Symbiotics are being tested. This product works with a plant’s natural defenses to repel corn rootworm larvae. However, researchers like Hodgson and Nick Seiter from the University of Illinois caution that the practical application of such products is still uncertain, and farmers should evaluate their effectiveness on a case-by-case basis.