Crops engineered to produce insecticidal proteins from the bacteria Bacillus thuringiensis (Bt) have had many noteworthy successes in the past 25 years, but resistance to Bt crops has evolved in numerous instances, as well. A new research review examines global patterns of resistance to Bt crops and outlines strategies for maximizing sustainability of this important tool for pest management.
As fall armyworm continues to threaten food security in Africa, the use of Bt maize offers significant potential to manage the pest. But it will be critical to manage resistance via multi-toxin crop varieties and appropriate use of refuge planting—all in forms accessible to the smallholder farmers that grow nearly all of Africa's maize.
A survey of corn farmers in Iowa shows which insect pests are of most concern and that most are not seeing failures in management methods such as Bt crops. But they do look to IPM and extension agents for guidance in managing insecticide resistance.
On smallholder farms using Bt maize in Africa, the combination of reduced field size and multiple pests presents challenges to insecticide resistance management. A new report in the open-access Journal of Integrated Pest Management offers recommendations for best practices.
A new article in the Journal of Economic Entomology examines varying levels of resistance to Bt toxins developed by the pink bollworm in the United States, China, and India over the last 20 years, illustrating the importance of incorporating refuge crops in Bt systems.