بررسی اثر زیر کشندگی عصاره های سیر روی میزان تفریخ تخم سفید بالک گلخانه

The greenhouse whitefly, Trialeurodes vaporariorum (Westood) (Hemiptera: Aleyrodidae( is an important pests in greenhouse, vegetable and ornamental plants. Regarding to high damages of this pest in addition to harmful effects of the chemical pesticides, applying some harmless and safe compound such as, botanical pesticides can be appropriate to control the pest. In this study, sub-lethal effect of garlic (Allium sativum) extracts including ethanol and acetic acid extract on hatching rate of the eggs of T. vaporariorum were investigated after 10 days. The whitefly colony was reared on the Phaseolus vulgaris leaves. In order to study the effect of garlic extracts, the concentrations ‎50 mg/ml in ethanol and acetic acid of garlic extracts were applied on the eggs of T. vaporariorum ‎on Phaseolus vulgaris leaves on laboratory condition (‎25±1°С temperature, 50±10% humidity and under a photoperiod of 16L:8D h)‎ and the hatching rate- data’s were obtained and analyzed with Stat plus (Fisher LSD Test) statistic program. Bioassay test was performed by spraying test method by special sprayer. The means of the hatching rate (%) for garlic acetic acid extract, acetic acid, ethanol, garlic ethanol extract and control were recorded 9.84±4.42, 40.96±6.21, 52.10±6.33, 61.12±4.62, 84.69±2.51, respectively. The means comparison among different treatments have shown that, the highest and least hatching rate were obtained with garlic acetic acid extract, respectively (p<0.05). Generally, results of this study show that the extracts of Allium sativum can be considered as an effective biopesticide to management and reduction of population of greenhouse whitefly. These compounds have acted as fumigant, contact insecticides, repellent, inhibition of oviposition and feeding, and affected insect population growth.