Variation in P450-mediated fenvalerate resistance levels is not correlated with CYP337B3 genotype in Chinese populations of Helicoverpa armigera

- Fenvalerate resistance in Chinese populations is largely due to P450-based metabolism.
- CYP337B3v2 is at high frequency in these populations of Helicoverpa  armigera.
- There is little correlation between the level of resistance and CYP337B3v2 frequency.
- Much of the fenvalerate resistance in China is explained by P450s beyond CYP337B3.