بررسی استفاده از آنزیم کلسترول اکسیداز روی میزبان و اثر آن روی جمعیت شب‌پره مینوزگوجه‌فرنگی Tuta absoluta Meyrick (Lep., Gelechidae)

The Tomato leafminer moth, Tuta absoluta Myrick. (Lep., Gelechiidae) is an important pest of cultivated tomato (Solanum lycopersicum) in Iran and other countries throughout the world. This pest damages on tomato and other crops economically due to high fecundity and short generation period. Using safer insecticides, such as enzymes and proteins, whith different modes of action and lower possibility of development of resistance would be useful for an effective control program. Choleterol oxidase enzyme was introduced as symbol of new protein and forth generation biological pesticides. The fatal effect of this enzymes is through inhibition of digesting the protein in the digestive system of insects. The aim of this study is investigation the effects of Choleterol oxidase enzyme on feeding behavior of T. absoluta and induced resistance in tomato plants. In this study, two concentrations of Choleterol oxidase (0.6 and 0.4 mg/l) and the Potasium phosphate (as control) were evaluated with foliar spray method on ezmir and ergon tomato cultivars under (22±5 ºC, 65±5% RH and 16:8 h L:D) conditions in 20 replicates. Resulted data including oviposition, longevity and survival rate of immature stage of T, absoluta was analyzed using spss-statistices. The results indicated the highest and lowest mean generation time for insects fed on ergon cultivar with 0.6 mg/l of enzyme (52/92±0.97047) and ezmir cultivar as control (49/37±0.74652), respectively. Significant differences observed between control and treatments. Induced resistance significantly reduced the oviposition of the adult T, absoluta, thereby, the lowest oviposition were observed on ezmir and ergon cultivar cultivars with 0.6 mg/l of enzymes equal to (49/71±0.81529) and (43/14±5.99773) respectively, while the highest were observed in control (92/5±5.86454) for both cultivars. Mean comparison indicated significant differences. Minimum survival rate of larvae and pupae was observed on ezmir cultivar with 0.4 mg/l of enzyme. Which indicated significant differences between control and other treatments. These results indicate that utilization of Cholesterol oxidase have a negative impact on survivorship, longevity and oviposition rate of the T. absoluta.and and may be suggested as a safe method for the management of this pest.