Document Type : Research Paper
Authors
1
Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran
2
Tea Research center, Horticultural Science Research Institute, Agricultural Research, Education and Extension organization (AREEO), Lahijan, Iran
Abstract
Tea mealybug, Pseudococcus viburni (Signoret) is one of the important pests of tea and citrus orchards in Northern provinces of Iran. In the current study, the effect of several plant-based insecticides and microemulsion formulaion of Sophora pachycarpa leaf and root extract were investigated against tea mealybug under laboratory conditions by leaf dip method. The LC50 values of matrine, pepper extract, cinnamon and garlic essential oil, neem oil, coconut oil soap, castor oil, formulated leaf and root extracts of S. pachycarpa, and espiromesifen were determined as 2157, 1538, 2825, 5608, 4746, 6585, 4493, 5357 and 2676 mg formulated/l on adult of the tea mealybug, respectively. In addition, the LC50 of aforementioned compounds was calculated as 2188, 1555, 2809, 5559, 4703, 5842, 3457, 5195 and 1856mg formulated/l for third instar nymph of this insect, respectively. The bioassays showed that pepper extract, matrine, and cinnamon and garlic essential oil were most efficient treatments against tea mealybug. Treatments of third instar nymphs by the insecticides also affected the activity of detoxifying enzymes including alpha- and beta-esterases, acetylcholinesterase, glutathione S-transferase (GST) and MFO system. Pepper extract, cinnamon and garlic essential oil, and formulated leaf extract of S. pachycarpa decreased the activities of α-esterase. Since the pepper extract, matrine, cinnamon and garlic essential oil showed significant mortality against nymphs and adults of the tea mealybug these insecticides can be considered in the integrated management of the tea mealybug.
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