Biology and life table analysis of Tetranychus urticae (Acari: Tetranychidae) on different common pea and bean cultivars

Abstract

The quality of the important host plants affects the survival, development, and reproduction of the two-spotted spider mite, Tetranychus urticae Koch. The biology and life table parameters of T. urticae, on four cultivars of common Regular and Sweet pea and Polesta & G6 bean, were examined under laboratory conditions of 27 ± 1 ℃, 60–80% R.H. and photoperiod 16L: 8D h. Both males and females of T. urticae successfully developed from egg to adult on different host plants. Results revealed that the survival rate varied from 53% on Regular pea to 99% on G6 bean cultivars. The developmental time from egg to adult was significantly influenced among the tested host plant cultivars and ranged from 9.75 days on G6 bean to 20.42 days on Regular pea (p = 0.00). Female longevity was significantly longer on Regular and Sweet pea than on Polesta and G6 bean. The highest fecundity per female was recorded on G6 bean, but the lowest was on Regular pea cultivars. Consequently, population growth parameters were also significantly influenced by different host plants. The net reproductive rate (R0), the intrinsic rate of natural increase (r), and the finite rate of increase (λ) of T. urticae were significantly higher on G6 bean than the other three cultivars. Also, the longest mean generation time (T) and doubling time (DT) were noted on Regular pea, but the shortest value on G6 and Polesta bean cultivars. Obtained results based on the intrinsic rate of natural increase revealed that G6 and Polesta bean were more suitable than the two pea cultivars as hosts for T. urticae. Therefore, the lower population growth rate of the T. urticae could be the result of antibiotic resistance in the cultivars Regular and Sweet pea.