Effects of alpha-cypermethrin + teflubenzuron on the mortality, ‎biological features and life-table parameters of tomato ‎leafminer, Tuta absoluta (Lep.: Gelechiidae), on two varieties of ‎tomato

The tomato leaf miner, Tuta absoluta (Meyrick), is one of the important pests of tomato in Iran. In the present study, the lethal and sublethal effects of the insecticide alpha-cypermethrin + teflubenzuron by leaf dipping method were investigated against the second-instar larvae of the tomato leafminer on Early Urbana Y and Super strain B tomato cultivars. The results showed that the toxicity of alpha-cypermethrin + teflubenzuron to tomato leafminer larvae in the Early Urbana Y variety (LC50 = 4509 ppm) is more than its toxicity in the Super strain B (LC50 = 5595 ppm). Treatment with alpha-cypermethrin + teflubenzuron increased the larval and pupal periods and developmental time of the tomato leafminer in the Early Urbana Y compared to the Super Strain B and control group. The lowest longevity and fecundity of the tomato leafminer were observed in the Early Urbana Y. The life-table parameters of the pest, including intrinsic rate of increase (r) and finite rate of increase (λ), on the Early Urbana Y treated by alpha-cypermethrin + teflubenzuron (0.0479 and 1.0491 day-1, respectively) were significantly lower than corresponding amounts on the treated Super Strain B (0.0684 and 1.0708 day-1, respectively). Treatment with alpha-cypermethrin + teflubenzuron increased the mean duration of a generation (T) of pest compared to the control. The results of the present study indicated that the use of alpha-cypermethrin + teflubenzuron on the Early Urbana Y variety in the management of T. absoluta could be more effective than the Super strain B variety.