Bt crops

Entomologists across the Midwest and South say a commonly used strategy to preserve the potency of GE corn that makes its own insect-repelling toxins, known as "refuge in a bag," "may actually increase the risk of Bt resistance in above-ground insects, particularly in the southern United States," reports DTN.

Monsanto Co. has threatened to pull out of India if the government goes forward with a plan to cut royalty fees on Bt cotton seeds by 70 percent, says Reuters.

Seed companies will be required to encourage corn growers to take steps to keep rootworms from developing resistance to the the biopesticide known as Bt, reports DTN.

A University of Arizona survey of 77 studies, released in 2013, found "well-documented cases of field-evolved resistance to Bt crops in five major pests as of 2010, compared with only one case in 2005.