Evolution of resistance to transgenic Bacillus thuringiensis maize in pest insects and a strategy for managing this

Author of the article:WANG Yue-Qin** HE Kang-Lai WANG Zhen-Ying***

Author's Workplace：State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China

Key Words：transgenic Bacillus thuringiensis maize; target pests; field resistance; resistance management

Abstract： Transgenic Bacillus thuringiensis maize expressing Bt toxins is a new tool for controlling target pest insects. However, the evolution of resistance within target pest populations threatens the sustainable utilization of Bt maize. By 2018 about 13 cases of resistance to Bt maize have been reported. In 5 other cases there was no significant decrease in susceptibility to Bt maize, including transgenic maize that produces the Vip3Aa protein. Factors that favor a successful resistance management strategy that can delay resistance include high-dosages, the recessive inheritance of resistance, low frequency of the alleles that confer resistance, incomplete resistance and fitness costs. When the inheritance of resistance is not recessive, increasing the size of refugia can still significantly delay the development of resistance.