B. Oppert et al., Fitness costs of resistance to Bacillus thuringiensis in the Indianmeal moth, Plodia interpunctella, ENT EXP APP, 96(3), 2000, pp. 281-287
Genetic changes in insects that result in insecticide resistance can also a
ffect their fitness. Here, we report measurements of development time and s
urvival of the Indianmeal moth, Plodia interpunctella (Hubner), to compare
the relative fitness of Bacillus thuringiensis (Bt)-susceptible and -resist
ant colonies. Measurements of larval development time and survival indicate
d that a fitness cost was associated with resistance to Bt in some Bt-resis
tant colonies but not others. Comparisons of geographically different popul
ations revealed inherent differences in development time and survival. In m
ost cases, Bt-resistant moths suffered no disadvantage when feeding on a Bt
-treated diet. In many cases, the development of Bt-resistant moths on Bt-t
reated diet was slower than the unselected moths on untreated diet, but it
is unclear whether these differences would affect the successful mating of
susceptible and resistant moths.