Evaluation of Amblyseius cucumeris Oudemans for Control of Pest Mites of Koerle Pear and Strategy for Its Practical Application

【Objective】 The study was carried out to estimate the efficacy of Amblyseius cucumeris Oudemans applied to control the pest mites in Koerle pear orchard in Xinjiang Autonomous Region.【Method】The life table parameters of A. cucumeris Oudemans and Tetranychus turkestani (Ugarav et Nikolski) under different temperatures and the efficacy of releasing A. cucumeris to control pest mites of Koerle pear were studied. 【Result】A. cucumeris could prey at all stages on T. turkestani. The generation survival rates of A.cucumeris was 100% within the temperature range from 19℃ to 31℃, but decreased by 50% at 33-34℃. The average fecundity of A. cucumeris was 33-47 eggs per female from 19℃ to 31℃. The rate of female of T. turkestani was 84.0%-85.0%, while the rate of female of A. cucumeris was 56.1%-58.2%. The net reproductive rates (R0) per generation of T. turkestani were 103.1%, 130.5% and 120.3% higher than those of A. cucumeris under 20℃, 25℃ and 30℃, respectively. The intrinsic rates of natural increase (rm) of T. turkestani were 20.5%, 33.7% and 64.9% higher than those of A. cucumeris, respectively. 【Conclusion】 Based on the biology of predatory and pest mites and environment conditions of orchard, It was suggested that it is the basic strategy for using A. cucumeris as a bio-control agent against pest mites. Field trial showed that if A. cucumeris is released in late April to early May when the temperature is 15-30℃ and there are not more than 2 pest mites per leaf, the pest mites could be controlled in the Koerle pear field effectively, and pesticide application could be reduced by 6-7 times in the whole season in the orchard with release of A. cucumeris.