The effects of the abamectin and spirodiclofen mixture on life history and population parameters of Amblyseius swirskii

Abstract

In this study, three sublethal concentrations (LC5, LC15, and LC25) of Envidor®speed (Abamectin and Spirodiclofen mixture, 24% SC, Bayer co.) on the biological parameters of the predatory mite Amblyseius swirskii Athias-Heneroit (Acari: Phytoseiidae) fed on Tetranychus urticae Koch (Acari: Tetranychidae) was assessed based on the Two-sex life table theory under laboratory conditions (25 ± 1°C, 70 ± 5% RH and 16:8 (L: D) hours). The data were analyzed based on a two-sex life table procedure. Increasing the sublethal concentration did have a significant effect on some life table parameters. The total lifespan of both males and females treated mites had a decreasing trend, for the females, it increased from 22.10 days in LC25 treatment to 42.67 days in control. The oviposition days of the predatory mite had the most differences between the LC15 and LC25 treatments compared to LC5 and control. Based on our results, the total fecundity is also affected by the acaricidal doses, which changed from 19.10 eggs per individual in LC25 to 37.17 eggs per individual in control. The net reproductive rate (R0), as well as the gross reproductive rate (GRR), were all significantly reduced with increasing the acaricide concentration. The control treatment had the maximum value, and the higher concentration treatment (LC25) had the slowest value of R0 and GRR. On the contrary, the intrinsic rate of increase (r) and finite rate of increase (λ) showed no significant differences with the increasing concentration of acaricide from the control to LC25 treatments. Eventually, with due attention to the large range value of each LCs for predatory mites concerning recommended concentration for T. urticae based on the active ingredient, the recommended concentration of Envidorspeed in IPM programs is unobstructed.