While organic farmers have used Bt proteins in sprays successfully for more than half a century, some scientists feared that widespread use of Bt proteins in genetically engineered crops would spur rapid evolution of resistance in pests.
Researchers at the University of Arizona have taken stock to address this concern and to discover why pests adapted quickly in some cases but not others. To test predictions about resistance, Bruce Tabashnik and Yves Carrière in the College of Agriculture and Life Sciences analyzed the global data on Bt crop use and pest responses [read the full study here (behind paywall)]
The researchers analyzed published data for 36 cases representing responses of 15 pest species in 10 countries on every continent except Antarctica. They discovered resistance that substantially reduced the efficacy of the Bt crops in the field in 16 cases as of 2016, compared with only three such cases by 2005. In these 16 cases, pests evolved resistance in an average time of just over five years.
“A silver lining is that in 17 other cases, pests have not evolved resistance to Bt crops,” Tabashnik said, adding that some crops continue to remain effective after 20 years.
The GLP aggregated and excerpted this article to reflect the diversity of news, opinion and analysis. Read full, original post: Research Shows Pest Resistance to Biotech Crops Is Surging