Definitions for terms related to resistance to pesticides updated
Emerging resistance of the western corn rootworm to Bt corn exemplifies the urgent need for well-defined resistance terms. The cost of this insidious beetle to U.S. corn growers has been estimated at one billion dollars annually. In 2003, to reduce costs and cut back on soil insecticides, U.S. farmers began planting Bt corn that kills rootworms.
"The first evidence of rootworm resistance to Bt corn was discovered in Iowa in 2009," said Dr. Bruce Tabashnik, the study's lead author and head of the entomology department at the University of Arizona. "Nearly five years later, the resistance has spread but decisive regulatory action by the EPA is still stalled, in part because an effective definition of resistance is lacking in this case."
Although some scientists have expressed concern that reports of pest resistance to Bt crops provide 'ammunition' to anti-biotech activists, Tabashnik said "Pests are remarkably adaptable. They usually evolve resistance to any tactic that's used repeatedly to control them, so this problem is not limited to transgenic crops." Noting that insects have been evolving resistance to natural plant defenses for millions of years and that this year marks the 100th anniversary of the first reported case of insecticide resistance, he concludes, "Finding ways to delay resistance is a never-ending challenge with any pest management approach."
The full article can be accessed at http://dx.doi.org/10.1603/EC13458