Abstract

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of melons. In this laboratory study, we used two-sex life table to evaluate the performance of T. urticae on five melon cultivars (IVF28, IVF118, IVF168, IVF437, and Yangjiaomi). We also evaluated the correlation between mite population growth and morphological characteristics of leaves. The results showed that the total immature time, adult longevity, total longevity, and fecundity of the spider mite differed among the cultivars. On IVF28, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.1638 d-1 and 1.1178 d-1, respectively, which were significantly lower than the values on IVF168, IVF118, or Yangjiaomi. Values for r and λ tended to be highest on IVF168. In addition, r values for T. urticae were not correlated with trichome density or stomatal density but were negatively correlated with melon leaf thickness. In summary, the different melon cultivars exhibited distinct levels of resistance to T. urticae and the IVF28 cultivar was considered the least favored for the growth and reproduction of T. urticae mites, and such differences of mite performance might be related to the leaf thickness, instead of trichome density or stomatal density.