Effects of sublethal concentrations of bifenthrin on the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae)

摘要

Bifenthrin is a broad-spectrum insecticide and acaricide that is widely used in China. We evaluated the effects of sublethal concentrations (LC10 and LC25) of bifenthrin on the eggs and adult females of the two-spotted spider mite, Tetranychus urticae, in the laboratory at 26 +/- 1 degrees C, 80% RH, and a 16 h: 8 h (L: D) photoperiod. The sublethal doses of bifenthrin decreased the intrinsic and finite rate of increase, net reproductive rate, survival rate, and reproductive value. The sublethal doses also increased the mean generation time, total pre-ovipositional period, and duration of the larval and nymphal stages. The intrinsic rate of increase dropped from 0.252/day in the control to 0.222 and 0.208/day in response to LC10 and LC25 treatments, respectively. Following LC10 and LC25 treatments, the net reproductive rate dropped from 60.65 offspring/individual in the control to 45.19 and 40.81, respectively. These laboratory results indicate that sublethal concentrations of bifenthrin may decrease the developmental rate of T. urticae, are unlikely to result in the resurgence of T. urtciae populations, and might therefore be useful in the integrated management of this pest.