Monsanto should enact a remedial action plan in fields where resistance to its Bt insecticide is suspected, the EPA said. That includes having growers use conventional pesticide to kill adult rootworm beetles late in the season and alternate pest control methods in the following season.

Monsanto tested rootworms for resistance in Nebraska, Illinois and Iowa and should expand the monitoring to Colorado, Minnesota, South Dakota and western Wisconsin because questions about the performance of Bt corn extends to all seven states, the EPA said in the memo.

Monsanto’s most advanced resistance problem is with crops engineered to tolerate its Roundup herbicide. Weeds that are no longer killed by Roundup have invaded 14 million acres of U.S. cotton, soybean and corn, according to Syngenta AG, a Swiss chemical maker. A Dow Chemical Co. study this year found as many as 20 million acres of corn and soybeans may be infested.

[What an incredible mess is being made with this. Life always finds a way. Try your best not to buy and eat these products (easier said than done, I know).]