Abstract: Tetranychus cinnabarinus (Boiduval), originating from Beibei, Chongqing, were continuously selected for resistance to fenpropathrin, abamectin and pyridaben. After 16 generations, resistance to fenpropathrin, abamectin and pyridaben had increased by 26.54-, 4.51-, and 1.16-fold, respectively. The realized heritability of resistance and resistance risk of T. cinnabarinus to these three acricides were evaluated using threshold trait analysis. The realized heritability of resistance to fenpropathrin, abamectin, and pyridaben was 0.2472, 0.1519, and 0.0160, respectively. Theoretically, to obtain a 10-fold increase in resistance requires 13-6 generations for fenpropathrin, 21-10 generations for abamectin, and 197-89 generations for pyridaben under selective pressure of 50%-90% mortality for each selective generation. Field populations would be expected to require more generations to obtain the same resistance levels. Of these three acaricides, the resistance risk was highest for fenpropathrin followed by abamectin and pyridaben. These results provide some basis for the management of pesticide resistance in T. cinnabarinus.

Key words: Tetranychus cinnabarinus, acricides, resistance, realized heritability, risk assessment