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.
Researchers in California tested several common insecticide baits used for management of German cockroaches (Blattella germanica) and found evidence of resistance to all but one bait in several field-caught populations.
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.
It may be only a matter of time before the Old World bollworm arrives in the U.S. A new guide in the Journal of Integrated Pest Management will help soybean growers and IPM pros be ready when it does.