Fields in Iowa, Illinois, Minnesota and Nebraska are suspected of developing tolerance to the plants’ insecticide, based on cases of severe crop damage from 2011, the EPA said in a memo. Monsantos program for monitoring this resistance is inadequate, the memo said. Monsanto issued a statement responding to the scientists' letter, asserting that rootworms has caused excessive damage on just 0.2 percent of the acres where farmers planted Monsanto's rootworm-protected corn.
http://www.monsanto.com/newsviews/Pages/bt-corn-performance-in-us-corn-belt.aspx
Scientists have recently released a public statement encouraging farmers to limit if not stop entirely the use of GM corn with the BT gene to prevent the spread of the insect before further gene strengthening occurs. A good read can be found below.
http://www.npr.org/blogs/thesalt/2012/03/08/148227668/insect-experts-issue-urgent-warning-on-using-gm-seeds
