Effect of Different Fertilizer Regimes on Life Table Parameters of Tetranychus urticae (Acari: Tetranychidae) on Resistant Bean Cultivar

Cultural methods such as crop fertilization can affect susceptibility of plants to herbivores by altering plant tissue nutrient. In this study, the life table parameters of the two-spotted spider mite (TSSM), Tetranychus urticae Koch were determined under different chemical fertilizer regimes on resistant bean cultivar (var. Parastoo) under laboratory conditions at 25 ±1 °C, 60 ±5% RH and a photoperiod of 16:8 (L:D) hour. Treatments included 30, 60, and 100% of the recommended level of urea, ammonium nitrate, and potassium sulfate fertilizers. According to the obtained results, the longest preadult development time was related to individuals reared on the fertilized bean with potassium sulfate 60%, while the shortest period was related to those on 30% ammonium nitrate and 60%urea. The mean fecundity of the individuals reared on fertilized beans with different concentrations of ammonium nitrate (especially 60% ammonium nitrate) were significantly higher than the other fertilizers. The highest and lowest values of intrinsic rate of increase (r) were obtained on beans fertilized with 60% ammonium nitrate and 100%potassium sulfate, respectively. In addition, the values of net Reproductive rate (R0) and the Gross Reproductive Rate (GRR) of TSSM reared on bean fertilized with 60% ammonium nitrate were significantly higher than the other fertilizer treatments. Our findings may provide important information in the design of a comprehensive program for integrated soil fertility management and subsequently integrated management of TSSM in bean fields.