Figure 3. Fluorescence polarization of mitochondrial membranes from both untreated (white bars) and treated larvae of P. xylostellas (solid bars). The concentration 0.011 mg/L was the dose to kill 50% individuals of XH-S strain, but no lethal to AV-R strain. The concentration 11.86 mg/L was the dose to kill 50% individuals of AV-R strain. The P. xylostella larvae were treated by leaf-dipping method. The significance of the differences between the two groups was determined by the Student’s t-test. The difference was considered significant at p<0.05, showed by *; for p<0.01, showed by **; NS, not significant.