BY SCOTT KILMAN
Widely grown corn plants that Monsanto Co. genetically modified to thwart a voracious bug are falling prey to that very pest in a few Iowa fields, the first time a major Midwest scourge has developed resistance to a genetically modified crop.
The discovery raises concerns that the way some farmers are using biotech crops could spawn superbugs.
Iowa State University entomologist Aaron Gassmann’s discovery that western corn rootworms in four northeast Iowa fields have evolved to resist the natural pesticide made by Monsanto’s corn plant could encourage some farmers to switch to insect-proof seeds sold by competitors of the St….