Frequency and fitness cost of resistance to Bacillus thuringiensis in Chrysomela tremulae (Coleoptera: Chrysomelidae)

Pest adaptation to transgenic plants producing 'Bacillus thuringiensis' (Bt) toxins can be delayed or prevented by the 'high dose-refuge' (HDR) strategy whose efficacy depends primarily on the initial frequency of Bt resistance alleles and on the fitness costs associated with these alleles. A study has concluded that resistance to Bt plants may be present at detectable frequencies in pest populations before selection resulting from pest management by humans.