Map Showing Resistance to Bt Toxins (image) University of Arizona Share Print E-Mail Caption Introduction of transgenic crops producing two or more Bt toxins has been spurred in part by pest resistance to transgenic crops that produce only one toxin. Red circles show the seven cases where pest resistance has reduced control of a target pest by a Bt crop, the other circles depict the resistance status in 20 other cases. Credit Bruce Tabashnik/University of Arizona Usage Restrictions This visual may only be used in conjunction with reporting or posting of this news release. Credit must be given 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.