Source: Christian Krupke, Purdue University

Bags of corn seed that mix genetically modified hybrids with and without Bt toxins that kill insects provide farmers easier compliance with federal regulations but could, over time, hasten insect resistance to Bt, a Purdue University entomologist said.

Although "refuge-in-a-bag" seed technology has been approved for use by the U.S. Environmental Protection Agency, questions still remain over its long-term effect on corn rootworms, the main pest targeted by the technology, said Christian Krupke.

"Is a guarantee of 100 percent grower compliance with refuge regulations for corn rootworms worth a bit of a risk in terms of resistance development?" he said. "For many the answer is yes, because compliance has been declining in recent years."

Refuge-in-a-bag products contain 90 percent Bt corn seed with 10 percent non-Bt "refuge" seed. 

Read more of Krupke's point of view