Demographic Analysis of the Effect of Fenpyroximate on Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae)

The effect of fenpyroximate on life table parameters of Phytoseiulus persimilis (Athias-Henriot 1957) was evaluated under laboratory conditions (25 +/- 2 degrees C, 60 +/- 5 % RH and 16:8 (L:D) h). To take both sexes and the variable developmental rate among individuals into consideration, the raw data were analyzed based on the age stage, two sex life tables. The estimated value of LC50 for P persimilis is found to be 270 ppm. The preoviposition period of P persimilis treated with fenpyroximate (1.67 d) was significantly longer than for the control treatment (1 d). The lifetime fecundity of P persimilis treated with fenpyroximate was 0.997 (egg/female) and for control treatment was 23.881 (egg/female). The intrinsic rate of increase (r), finite rate of increase (lambda), net reproductive rate (R-0), the mean generation time (T) and gross reproduction rates (GRR) of P persimilis treated with fenpyroximate were obtained as -0.023 d(-1), 0.977 d(-1), 0.724 offspring, 12.812 d and 3.981 offspring, respectively. Results showed that fenpyroximate had a significant negative effect on life table parameters of P persimilis and indicate that fenpyroximate in combination with P persimilis should not be used together at the same time in integrated pest management programs aimed at control of Tetranychus urticae (Koch 1836).