Several seed companies reported a threefold increase last year in U.S. farmers caught violating rules intended to stop insects from developing resistance to genetically modified corn. The rules affect farmers planting seeds modified to produce a toxin derived from Bacillus thuringiensis, or Bt, a natural insecticide. The Environmental Protection Agency requires those growers to also plant an adjacent area of non-Bt corn so that bugs feed on both types of corn and don’t become immune to the toxin.
Monsanto reports that about 41 percent of 3,053 farmers inspected in 2011 failed to fully comply with the refuge requirement. Seed companies are concerned that bugs’ resistance to modified crops may be increasing. Joanne Carden of Monsanto says – farmers who violate the requirements are now revisited at least twice over five years. Those who fail the follow-up inspection will lose access to the technology.
In July, Iowa State University found that some rootworms have evolved resistance to the Bt gene engineered into Monsanto corn. Entomologists in Illinois and other Midwestern states are studying possible resistance in fields where the insects devour roots of Monsanto’s Bt corn.