Evaluation of the Different Control Methods for the Two-Spotted Spider Mites by Computer Software and Percentage Efficacy

摘要

The trials were carried out, under greenhouse conditions in Ankara-Turkey to control the two spotted spider mite (TSSM) Tetranychus urticae Koch as part of a mite management program in 2007 season, on cucumber ( Cucumis sativus L.). Three different control methods namely, chemical (by using hexythiazox, bifenthrin and dimethoate), biological (by releasing Phytoseiulus persimilis and Amblyseius californicus ) and combination between chemical and biological control were applied and evaluated by two different methods. One of them, depended on measuring the feeding damage rate of TSSM by computer software (Compu Eye, leaf and Symptom Area). The other one is common in used and rely on calculation the percentage efficacy by mathematical formula (Henderson and Tilton formula). The ANOVA analysis of results of the tested evaluation methods could separate the mean of values of percentage efficacy and feeding damage rate and relatively assemble into counterpart groups and gave same decision in evaluation the effectiveness of the control methods. The results indicated that hexythiazox and dimethoate could not repress the TSSM population, which gave significant damage rate in its treatments and the efficacy of mention pesticides not provided well controlling, which was low to TSSM when compared with bifenthrin, predators and combination of chemical and predators. While, bifenthrin and hexythiazox combined with predators or bifenthrin alone could repress well the TSSM population so that, the damage rate was low, which its percentage efficacy was high. Feeding damage rate, which was assessed by computer software may be satisfactory recommend to evaluate the effectiveness of control methods against spider mites under IPM programs.