1- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box 14115–336, Tehran, Islamic Republic of Iran.
2- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran. , a.mikani@modares.ac.ir
3- Iranian Research Institute of Plant Protection, Agricultural Research Education and Extension Organization (AREEO), Tehran, Islamic Republic of Iran.
Abstract: (2809 Views)
Cabbage aphid, Brevicoryne brassicae (L.) (Hom.: Aphididae) is an important pest of crucifers and is controlled by different insecticides, especially dimethoate.The toxicity of dimethoate in six populations of the pest from different parts of Iran was assayed using Leaf-dip method. The bioassay results indicated significant difference in susceptibility to dimethoate among the six populations that were investigated. The highest level of resistance to dimethoate was obtained for Mehrshahr (Meh) population (RR= 91.25). Diethyl maleate (DEM), ,piperonylbutoxide (PBO), and triphenyl phosphate (TPP) suppressed the level of resistance to dimethoate, indicating the resistance to this insecticide was caused by glutathione S-transferases (GSTs), mixed function oxidases, and esterases, respectively. Cytochrome P450 monooxygenases and GSTs activity increased, respectively, 2.7 and 9.6-fold in resistant population compared with the susceptible one. When α-naphthyl acetate was used as substrate, up to 4-fold increase in esterase activity was observed in resistant population. Moreover, 6.2-fold elevation in esterase activity was shown in resistant strain when β-naphthyl acetate was the substrate. Overall, the mechanisms of insecticide resistance in cabbage aphid populations from six regions of Iran were related to GSTs, esterase, and cytochrome P450 monooxygenases activities.
Article Type:
Original Research |
Subject:
Agricultural Economics/Agriculture Marketing and Supply Chains Received: 2018/09/24 | Accepted: 2019/01/29 | Published: 2020/01/30