Costas Ch Voudouris1,2, Amalia N Kati3, Eldem Sadikoglou4, Martin Williamson5, Panagiotis J Skouras6, Ourania Dimotsiou3, Stella Georgiou1, Brian Fenton7, George Skavdis4, John T Margaritopoulos1. 1. Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece. 2. Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Crete, Greece. 3. Plant Pathology Laboratory, School of Agriculture, Aristotle University of Thessaloniki, Thessaloniki, Greece. 4. Department of Molecular Biology and Genetics, Democritus University of Thrace, Dragana, Alexandroupolis, Greece. 5. Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, Herts, UK. 6. Laboratory of Agricultural Entomology and Zoology, Department of Agricultural Technologies, Technological Educational Institute of Peloponnese, Antikalamos, Kalamata, Greece. 7. Crop and Soil Systems Research Group, Scottish Rural University College, Aberdeen, UK.
Abstract
BACKGROUND: Myzus persicae nicotianae is an important pest in Greece, controlled mainly by neonicotinoids. Monitoring of the aphid populations for resistance mechanisms is essential for effective control. RESULTS: Two new RFLP-based diagnostics for the detection of the M918T (super-kdr pyrethroid resistance) and nAChR R81T (neonicotinoid resistance) mutations were applied, along with other established assays, on 131 nicotianae multilocus genotypes (MLGs) collected from tobacco and peach in Greece in 2012-2013. Furthermore, we present resistance data from aphid clones (>500, mainly nicotianae) collected in 2006-2007. About half of the clones tested with a diagnostic dose of imidacloprid were tolerant. The R81T mutation was not found in the 131 MLGs and 152 clones examined. Over half (58.6%) of a subset of 29 clones showed a 9-36-fold overexpression of CYP6CY3. M918T was found at low to moderate frequencies. The kdr and MACE mechanisms and carboxylesterase-based resistance were found at high frequency in all years. CONCLUSION: The aphid retains costly resistance mechanisms even in the absence of pressure from certain insecticides, which could be attributed to factors related to climate and genetic properties of the populations. The indication of build-up of resistance/tolerance to neonicotinoids, related to CYP6CY3 overexpression, is a matter of concern.
BACKGROUND:Myzus persicae nicotianae is an important pest in Greece, controlled mainly by neonicotinoids. Monitoring of the aphid populations for resistance mechanisms is essential for effective control. RESULTS: Two new RFLP-based diagnostics for the detection of the M918T (super-kdr pyrethroid resistance) and nAChR R81T (neonicotinoid resistance) mutations were applied, along with other established assays, on 131 nicotianae multilocus genotypes (MLGs) collected from tobacco and peach in Greece in 2012-2013. Furthermore, we present resistance data from aphid clones (>500, mainly nicotianae) collected in 2006-2007. About half of the clones tested with a diagnostic dose of imidacloprid were tolerant. The R81T mutation was not found in the 131 MLGs and 152 clones examined. Over half (58.6%) of a subset of 29 clones showed a 9-36-fold overexpression of CYP6CY3. M918T was found at low to moderate frequencies. The kdr and MACE mechanisms and carboxylesterase-based resistance were found at high frequency in all years. CONCLUSION: The aphid retains costly resistance mechanisms even in the absence of pressure from certain insecticides, which could be attributed to factors related to climate and genetic properties of the populations. The indication of build-up of resistance/tolerance to neonicotinoids, related to CYP6CY3 overexpression, is a matter of concern.