On November 28, 2011, the U.S. Environmental Protection Agency (EPA) released a memo which identified the failure of Monsanto’s Bt corn to prevent “unexpected” rootworm damage to the corn crop. The EPA stated that at least four states, Iowa, Illinois, Minnesota, and Nebraska, are seeing “severe efficacy issues” for Monsanto’s Bt corn. The agency also noted problem areas in four additional states, Colorado, South Dakota, Minnesota, and western Wisconsin, and asked that they be monitored in the future.

Shaking its regulatory finger at Monsanto, the EPA said in no uncertain terms that the company’s resistance monitoring is “inadequate and likely to miss early resistance events.”