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Rootworms Developing Cross-Resistance to Various GMO Crops & Pesticides


Pesticide-resistant rootworms that have recently become a problem for Midwest farms growing Monsanto's genetically modified corn are now showing tolerance to Syngenta's GMO corn and chemicals as well, cites new research.

Rootworms were first noted last year as developing resistance to Monsanto's popular Roundup—the glyphosate-based pesticide used in tandem with the company's Roundup Ready seeds such as corn and soy. Farmers in Iowa, Illinois, Nebraska and Minnesota have begun using stronger chemicals the crops were designed not to use because of the resistance the pests have developed to glyphosate.

Pesticides made by Syngenta, the Swiss crop chemical and genetically modified seed producer that competes for much of the same market as Monsanto, are now also showing signs of resistance from rootworms, according to research out of the University of Missouri and the USDA. The researchers presented their findings at the recent annual meeting of the Entomological Society of America in Knoxville, Tennessee. The most startling reveal was that the even though Syngenta's corn and chemicals had not been yet planted in the same fields as the Monsanto corn, rootworms have already showed similar resistance levels to Syngenta's pesticides in experimental laboratory fields, in a trait that's being called "cross-resistance."

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From the Organic Authority Files

Rootworms are responsible for extensive damage estimated at $1 billion annually, cites the USDA. According to, Dirk Benson, Syngenta’s head of trait projects said, “This has been the most difficult insect to control in the Corn Belt in my lifetime.”

New strains of GMO crops are now being developed to resist stronger pesticides that can combat the rootworms, but critics of GMO technology anticipate rootworms and other threats like "superweeds" developing the resistance to those chemicals as well eventually.

Keep in touch with Jill on Twitter @jillettinger

Image: Jan Tik

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