The sublethal concentration of Cyflumetofen adversely affect demographic parameters of Tetranychus urticae (Acari: Tetranychidae): Using age-stage, two-sex life tables

Abstract

ABSTRACT The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) has an extensive host range and is the most important pest mite worldwide. Traditional control measures have on the application of the lethal dose of acaricides, thus underestimating the total effects of acaricides on the population dynamics. Our main objective was to evaluate whether it is possible to rely on sublethal concentrations of the pesticide to control mites without getting meaningful crop. To test this hypothesis, we used sublethal concentrations (including LC10, LC20, LC30) of cyflumetofen to see the impact on population parameters of T. urticae. The experiments were performed under laboratory conditions at 25 ± 2°C, 60 ± 5% relative humidity (RH), and a photoperiod of 16:8 (L: D) hours. Results were based on age-stage, two-sex life table analysis. The data showed that sublethal concentrations of the pesticide suppress fecundity, adult longevity (both female and male individuals), and the intrinsic rate of increase significantly. For example, the fecundity in the LC10, LC20, LC30 and control was 36.55, 42.26,and 57.96 eggs/female, respectively, showing significant differences. Similarly, the intrinsic rate of increase (r) are also significantly different between LC30 (r = 0.20) and the control (0.24). The data presented here raise awareness into mite control since using a lower pesticide concentration not only controls the pest population but also produces lower risk to the environment, consumers, and biocontrol agents. Therefore, one could infer that using sublethal concentrations of pesticides would be more beneficial to both the environment and consumers in the long run.