Development of resistance, mechanism of biochemical resi̇stance and cross resi̇stance in Tetranychus urticae koch population selected with spiromesifen+abamectin

In this study, resistance development to spiromesifen + abamectin mixture formulation, cross resistance rates to spiromesifen, spirodiclofen, abamectin, milbemectin and spirodiclofen + abamectin were determined in the Tetranychus urticae population selected with the spiromesifen + abamectin mixture. In addition, spiromesifen + abamectin resistance mechanisms have been demonstrated by biochemical methods. The study was carried out in three different stages. In the first step, LC50 and LC 90 values of spiromesifen + abamectin mixture were determined in the susceptible (GSS) population of T. urticae. The LC90 value of the susceptible population was accepted as the diagnostic dose and the selection study was started with this dose. In the second stage, it was determined whether cross resistance developed against spiromesifen, spirodiclofen, abamectin, milbemectin and spirodiclofen + abamectin in the population selected with spiromesifen + abamectin. In the third stage, some detoxification enzyme (esterase, glutathione-S-transferase (GST) and cytochrome P450 (P450)) activities were investigated in the population selected with spiromesifen + abamectin. Spiromesifen + abamectin LC50 and LC90 values in T. urticae susceptible (GSS) population were found as 0.222 μL / 100 mL and 1.107 μL / 100 mL water, respectively. In the population selected and named IR, the LC50 value increased to 266,874 μl / 100 mL water and the resistance ratio was 1199 fold. In cross-resistance studies, LC50 resistance ratios for spiromesifen, spirodiclofen, abamectin, milbemectin and spirodiclofen + abamectin were found to be 226609, 224, 1759, 40, 1069 fold, respectively. In biochemical studies, esterase, GST and P450 enzymes increased by 1.71, 2.57 and 2.58 fold, respectively, in the selection population (IR) compared to the sensitive population.