Field monitoring of Helicoverpa armigera (Lepidoptera: Noctuidae) Cry1Ac insecticidal protein resistance in China (2005-2017).

Compared to resistance level from 1998 to 2004 and the geographic baseline in different places of China in 1997, Bt resistance of H. armigera field populations to Cry1Ac protein has increased significantly, but failure of Bt cotton has not yet been detected. © 2018 Society of Chemical Industry.