Investigation of the effect levels of some active substances against (Acarina:Tetranychidae) Abamectin-resistant Tetranychus urticae Koch. population from Antalya

Two-spotted spider mite Tetranychus urticae Koch. (Acarina: Tetranychidae) is one of the harmful mite species that is common in Turkey and many countries of the world and causes significant losses in agricultural products. The increasing prevalence of populations resistant to many active substances has weakened the effectiveness of pesticides used in the management against this species.With the studies carried out within the scope of the thesis, the efficacy potential of plant protection products with different mechanisms of action, Beauveria bassiana ATCC 74040 strain, Terponoid Blend QRD460, Spiromesifen+Abamectin and Chlorantraniliprole+Abamectin against the Abamectin-Resistant T. urticae population. In addition, a selection study was conducted with the entomopathogen B. bassiana ATCC 74040 strain, which is expected to be used more widely in the future, and the potential for resistance to this entomopathogen in T. urticae was investigated. LC values and resistance ratios were determined by laboratory mite-dip tests conducted on laboratory and Abamectin-Resistant populations for the effect potentials of the plant protection products tested in the thesis.In the mite-dip test, first of all, adult female spider mites were left on the cowpea leaf discs. These discs were dipped for 5 seconds in a series of doses that caused 0-100% mortality in the population, and after drying, they were placed in a petri dish with agar and kept in the climate chamber until counting time. For B. bassiana ATCC 74040, no significant difference was found between the LC values from the Abamectin-Resistant and Laboratory populations. The LC50 values for the Abamectin-Resistant and Laboratory populations are 0.5×107 and 0.4×106 spore/ml, respectively. B. bassiana at the recommended dose resulted in close mortality in both populations. Mortality rates at the recommended dose in the Abamectine-Resistant and Laboratory populations were 97% and 100%, respectively. The LC50 values obtained in the tests performed on the population selected with B. bassiana ATCC 74040 strain and on the Laboratory population were 3.9×107 and 0.4×106 spore/ml, respectively. The population selected with B. bassiana ATCC 74040 strain was found to be approximately 9 times more resistant than the unselected population, and this difference is important because the confidence intervals of the LC values of the populations do not overlap. Tests with Terpenoid Blend QRD 460 found no significant difference in LC values of T. urticae obtained in the Abamectin-Resistant and Laboratory populations.The LC50 values for the Abamectin-Resistant and Laboratory populations are 553.01 and 450.29 mg(active substance) /L, respectively. Terpenoid Blend Q 460 at the recommended dose resulted in close mortality in both populations.Mortality rates at the recommended dose in the Abamectin-Resistant and Laboratory populations were 56% and 57%, respectively. The LC50 values of the Laboratory and Abamectin-Resistant population were found to be 2.51 and 20.12 mg (active substance) /L, respectively, in tests performed with Spiromesifen+Abamectin. Containing two active ingredients, this acaricide killed 97% of the Laboratory population and 62% of the Abamectin-Resistant population at the recommended label dose. In the tests performed with Chlorantraniliprole+Abamectin, the LC50 values of the Laboratory and Abamectin-Resistant population were found to be 0.61 and 4.04 mg(active substance) /L, respectively. Chlorantraniliprole+Abamectin at the recommended dose was able to kill the entire Laboratory population, but was able to produce 82% mortality in the Abamectin-Resistant population.