The resistance levels against carbamates (CB) and organophosphates (OP) were determined through bioassay and quantitative sequencing (QS) methods in 16 field populations of Nilaparvata lugens. The resistance levels to CB and OP by bioassay were 1.3~47.5-fold and 1.4~14.4-fold higher than a susceptible strain, respectively. The QS protocol was established to determine the allele frequencies of eight point mutations on acetylcholinesterase putatively associated CB and OP resistance. The allele frequencies of four mutations in local populations (G119A, F/S330Y, F331H and I332L) ranged from ca. 0.0~51.7%, 1.0~44.3%, 8.5~57.3% and 7.12~56.6%, respectively. The average prediction limits were –9.6±5.1~7.7±2.9%. The F330Y, F331H and I332L were tightly linked each other, suggesting these mutations may occur simultaneously. In the correlation analysis, G119A was not well correlated with both insecticides (r2= less 0.25), whereas F/S330Y, F331H and I332L showed better correlation with the resistance levels of carbamate (r2=0.590) than organophosphate (r2=0.235). This finding indicates that F/S330Y, F331H and I332L mutation frequencies are suitable for detecting carbamate resistance in N. lugens. QS will be applicable for the rapid monitoring of resistance levels to CB insecticides in N. lugens.

• Deok Ho Kwon(Research Institute for Agriculture and Life Science, Seoul National University)
• Si Woo Lee(National Academy of Agricultural Science, Rural Development Administration)
• Ji Hyeon Park(Department of Agricultural Biotechnology, Seoul National University)
• Si Hyeock Lee(Research Institute for Agriculture and Life Science, Seoul National University, Department of Agricultural Biotechnology, Seoul National University)