Biotech Updates

Success of High-Dose/Refuge Resistance Management Strategy

September 9, 2011

Four major target pests of Bt crops in the USA and Canada - European corn borer, southwestern corn borer, tobacco budworm, and pink bollworm - remain susceptible to Bt toxins after 15 years of intensive use of Bt maize and Bt cotton. Implementation of the 'high-dose/refuge' insecticide resistance management (IRM) strategy substantially delayed field resistance to Bt crops. These research findings are reported by Fangneng Huang and colleagues published in the journal Entomologia Experimentalis Et Applicata.

Sustaining susceptibility in these major pests is attributed to the successful implementation of the 'high-dose/refuge' insecticide resistance management (IRM) strategy: 1) Bt crop cultivars express a 'high dose', 2) initial frequency of resistance alleles is very low, and 3) a refuge is maintained nearby in the environment.

Factors associated with cases of field resistance include failure to use high-dose Bt cultivars and lack of sufficient refuge.

An abstract of the research is at http://onlinelibrary.wiley.com/doi/10.1111/j.1570-7458.2011.01138.x/abstract.