| Insecticide resistance status of Tuta absoluta (Lepidoptera: Gelechiidae) and mechanisms involved in resistance |
| Paper ID : 1280-3IICE (R2) |
| Authors: |
|
Reihaneh Barati, Mir Jalil Hejazi * University of Tabriz |
| Abstract: |
| The tomato leaf miner, Tutaabsoluta, is a major destructive pest of tomato plants that has rapidly expanded in range. Low efficacy of available insecticides against this pest and its control failure have been reported. In this study, the toxicity of chlorpyrifos, deltamethrin, indoxacarb and chlorantraniliprole was determined againstsecond instar larvae of two Iraniangreenhouse populations of T. absolutafrom Soufian (SF) and Qom (QM) using a leaf-dip bioassay. The resistance status of the populations was investigated through synergism assays.The synergists used werePBO, DEF, DEM andTPPwhich are inhibitors of cytochrome P450-dependent monooxygenases, esterases, glutathioneS-transferases and carboxylesterases, respectively. Reduced susceptibility to the insecticides studied was observed in Soufian and Qom populations compared with the susceptible population which was reared in greenhouse for three years without exposure to any insecticides. In Qom population, the highest resistance ratio (RR50 ) belonged to indoxacarb (14.91) followed by chlorpyrifos (4.46), chlorantraniliprole (4.42) and deltamethrin (2.06). The highest RR50 in Soufian population belonged tochlorantraniliprole (8.37) followed by chlorpyrifos (7.41) and indoxacarb (6.71).In SF population, RR50 for deltamethrin couldnot be estimated due to leaf damage caused by the high concentrations of this pyrethroidinsecticide.InQM population,indoxacarb and chlorpyrifos were more toxic in presence of PBO than its absence showing synergistic ratios of 6.53 and 5.44, respectively. In addition, using PBO in SF population, the effects of chlorantraniliprole and chlorpyrifos were increased 5.14 and 4.86 times, respectively. The other synergists did not increase the toxicity of the insecticides tested.Provided that similar results are obtained in commercial greenhouse and field scale, these results can be useful in insecticide management of T. absoluta. |
| Keywords: |
| Tomato leaf miner, Pest management, Mechanisms of resistance, Synergistic effects, Piperonyl butoxide |
| Status : Paper Accepted (Oral Presentation) |
