Lethal and sublethal effects of cyenopyrafen on life table parameters of Tetranychus urticae in two consecutive generations in laboratory conditions

Tetranychus urticae Koch is one of the major pests of many agricultural crops. The application of effective pesticides with novel mechanism of action is one of the common strategies in integrated management programs. In the present study, the effect of different concentrations of cyenopyrafen were assesed on the biological parameters of the T. urticae in laboratory conditions (25±3 °C, 65±5% RH, and photoperiod 8:16 h (light: dark). The assessment was conducted through a spraying method and involved analyzing the age-stage, two-sex life table across two successive generations. The LC50 value of cyenopyrafen was determined to be 250.945 ppm for protonymph stage. Among the sublethal concentrations of LC10, LC20, and LC30, the LC30 concentration exhibited the most significant impact on biological and reproductive parameters. This concentration resulted in a decrease in the oviposition rate, a reduction in the duration of the oviposition period, and a shortened lifespan for both male and female individuals in the first generation. The sub-lethal concentrations of cyenopyrafen also affected the progeny of treated protonymphs and caused an increase in the duration of the egg, larvae, protonymph, and deutonymph stage and a decrease in the adult lifespan of the female from 22.26 to 18.21 days, and this process caused a reduction in the fecundity rate from 45.63 to 28.86 eggs and the length of the oviposition period from 17.13 to 13.17 days. Consequently, the intrinsic rate of population increase was diminished, recorded at 0.20±0.51 day-1 in the control group and 0.15±0.051 day-1 at the LC30 concentration, with the most pronounced negative impact observed at the LC30 level. The population growth trend observed at the LC30 sublethal concentration was slower compared to the control. It is advisable to examine the impact of cynopyrafen on T. urticae within both greenhouse and field conditions for its application in integrated management.