EPA is seeking public comment on a proposed framework intended to delay the corn rootworm pest becoming resistant to corn genetically engineered to produce Bt pesticides.  The Agency is open to suggestions for alternative approaches that would achieve this objective. The proposed framework includes requirements on the manufacturers of Bt corn including:

  • In areas at risk of corn rootworm resistance, require crop rotation; use of corn varieties containing more than one Bt toxin; or other Integrated Pest Management (IPM) strategies and stewardship for corn rootworm.
  • Develop and implement a strategy to better detect and address areas of resistance as they emerge.
  • Use different and improved scientific tests and sampling requirements to study the problem and more reliably ensure that resistance to the Bt corn toxin is identified. 

These measures and others are designed to significantly delay corn rootworms from developing resistance to Bt pesticides genetically engineered into corn (a plant-incorporated protectant or PIP). The proposed framework would change the way farmers use Bt corn, in order to slow the development of resistance. Our goal is to prolong the durability and effectiveness of these plants to control the corn rootworm pest.

 Use of PIP crops is one of the safest methods of insect control. If used properly, they greatly reduce the need for conventional pesticides and the risks they may present to human health and the environment. For these methods to continue to be available long into the future, it is essential that they remain effective. They must be managed properly to prevent insects from developing resistance to the natural proteins being expressed. EPA is committed to maintaining effective oversight of these products to preserve their substantial benefits to agriculture and the environment.

We are concerned about the corn rootworm’s development of resistance to Bt corn PIPs.  Recent reports have documented corn rootworm resistance to two Bt traits, Cry3Bb1 and mCry3A, in the U.S. Corn Belt. To obtain expert guidance on the best way to address these concerns, the Agency convened a Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (FIFRA SAP) meeting in December 2013. The panel evaluated EPA’s current resistance monitoring strategy for the corn rootworm and made recommendations for improvement. These proposed enhancements are consistent with the Science Advisory Panel’s (SAP) guidance. 

We are seeking input from all stakeholders, including corn growers, non-governmental organizations, industry, academia, and the general public, on this proposal. Stakeholders are encouraged to offer input on specific SAP recommendations, including alternative approaches or counter proposals to address corn rootworm resistance management issues raised by the panel.

EPA’s proposed framework is available under docket number EPA-HQ-OPP-2014-0805 at www.regulations.gov. Comments and suggestions for alternative approaches are due by March 16, 2015.

EPA's docket for general information on insect resistance management can be found under docket number, EPA-HQ-OPP-2011-0922

Information on plant-incorporated protectants can be found at:  www.epa.gov/pesticides/biopesticides/pips/.