The Effect of Fenpyroximate on Life Table Parameters of Tetranychus urticae under Laboratory Conditions

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Abstract

The effect of fenpyroximate on life table parameters of two-spotted spider mite Tetranychus urticae Koch was evaluated under laboratory conditions (25±20C, 60±5% RH and 16:8 L:D). Data were analyzed on the basis of age-stage, two-sex life table theory. The estimated value of LC50 for T. urticae was found to be 380 Ml/l. Durations of total preadult stage and preoviposition period in T. urticae treated with fenpyroximate (12.64 and 2.36 d, respectively) were significantly longer than those in control (11.56 and 1d, respectively). The lifetime fecundity of T. urticae treated with fenpyroximate was 1.35 (eggs/female) compared with control (52.27 eggs/female).The instric rate of increase (r), finite rate of increase (?), net reproductive rate (R0), the mean generation time (T) and Gross Reproduction Rate (GRR) in T. urticae treated with fenpyroximate were -0.001 d-1, 0.998 d, 0.96 offspring, 14.25 d, 2.94 offspring, respectively. The study shows that the LC50 of fenpyroximate decreases the fecundity of two-spotted spider mite under laboratory conditions and makes the pest population growth almost face extinction. So the acaricide can be effectively used in two-spotted spider mite control.

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