Determination of the resistance level of two-spotted spider mite (tetranychus urticae koch) populations in apple orchards in Isparta province against some pesticides

Abstract

Abstract: This study was conducted to determine the resistance of two-spotted spider mites to some pesticides (propargite, chlorpyrifos and abamectin) used in apple orchards around Isparta province where apple production is intense. The LC50 and LC90 levels of all populations to these pesticides were determined using Petri plate - spray tower method. The LC50 value of Tetranychus urticae Koch populations to propargite, chlorpyrifos and abamectin was found to be 137.69 – 295.07 μ l l-1 distilled water, 70.99 – 1219.46 μ l l-1 distilled water and 6.41 – 15.13 μ l l-1 distilled water, respectively. Resistant ratios of populations were calculated by dividing the LC50 values of field populations by that of a susceptible population of T. urticae strain GSS. The resistance ratios for all T. urticae populations ranged from