Resistance to Biotech Crops Is on the Rise (image) University of Arizona Share Print E-Mail Caption By 2011, the area planted worldwide to genetically engineered Bt corn and Bt cotton increased to 66 million hectares (160 million acres) and the number of pest species with resistance causing reducing efficacy of Bt crops climbed to five. The asterisk indicates the number of resistant pests could be underestimated for 2011 because reports of field-evolved resistance typically are published two or more years after resistance is first detected. Credit Image courtesy of Nature Biotechnology Usage Restrictions This visual may only be used in conjunction with reporting/posting of this news release. Image/video credit must be included exactly as indicated. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.