Sublethal Effects of Atropa belladonna Herbal Extract on Biological Performance of the Two-Spotted Spider Mite Tetranychus urticae Koch (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus urticae Koch (Acari- Tetranychidae) is one of the most important pests of agricultural products. Using chemical pesticides is one of the main methods for its management. Due to undesirable effects of synthetic pesticides, this research was conducted to achieve alternative safe compounds. In this study sublethal effect of Atropa belladonna herbal extract including LC10, LC20, LC30 and distilled water were evaluated on biological parameters (such as r, λ, GRR, R0 and T) of T. urticae. The experiments were done under laboratory condition at 25±2 °C, 60±5% RH, and a photoperiod of 16-8 (L- D) hours. The crude data were analyzed based on age-stage, two-sex life table analysis. The results indicated significant reduction in female’s duration of maturation, oviposition period and total fecundity by increasing examined dose. The highest and lowest values of the net reproductive rate (R0) were obtained 38.41 and 18.08 offspring/individual in control and LC30, respectively. The maximum values of intrinsic rate of increase (r) was 0.2201 day-1that occurred on control treatment while the minimum values was obtained 0.1937 day-1 in LC30 concentration. Finite rate of increase (λ) had significantly descended with concentration enhancing from LC20 to LC30, compared with the control. The results demonstrated that Atropa belladonna herbal extract could be incorporated in integrated pest management (IPM) programs of T. urticae.