Population growth parameters of Tetranychus urticae (Acari: Tetranychidae) on different bean varieties

Population growth parameters of Tetranychus urticae Koch on four bean varieties including Talash (Colorado bean), Sadaf (Navy bean), Goli (Kidney bean) and Parastoo (Black-eye bean) were investigated in laboratory conditions at 25 ± 1°C, 60 ± 5% RH and a photoperiod of 16: 8 (L: D) h. In this experiment, one-day old eggs of T. urticae were selected and reared in growth chamber until the death of the last female mite, and the survival rate and female progeny of the mite were measured. Net reproduction rate (R0) on four bean varieties, was 8.822, 3.622, 4.908 and 2.043, intrinsic rate of increase (rm) was 0.142, 0.079, 0.095 and 0.038, and finite rate of increase (λ) was 1.152, 1.082, 1.099 and 1.039, respectively. Mean generation time (T) was determined 15.381, 16.283, 16.715 and 18.308 and doubling time (DT) was 4.901, 8.787, 7.292 and 18.125 days, respectively. The results indicated that the rate of population growth of T. urticae on Talash variety was more than other varieties. The rates of population parameters on Parastoo variety were the least.