Bacillus thuringiensis (Bt) is widely used as a biopesticide worldwide. To date, at least eight pest species have been found to be resistant to Bt in the field. As the first pest that was reported having resistance to Bt in the field, considerable research has been done on the mechanisms of Bt resistance in Plutella xylostella . However, whether the acquisition of Bt resistance by P. xylostella comes at a fitness cost is also a valuable question. In this study, Aminopeptidase-N 2 ( APN2 ), a Cry toxin receptor gene of P. xylostella , was knocked down by RNA interference, resulting in improved ...
