Insecticide Resistance, Resistance Mechanisms, and Phylogeny of Three <em>Myzus persicae</em> Populations in Cabbage from Three Agroclimatic Zones of Sri Lanka

The aphid, Myzus persicae is an important sucking pest and a virus vector in many crops. management of M. mainly through synthetic pesticides. development resistance against common pesticides has resulted control failures persicae. objective this study was to examine the status pesticide genetic structure populations. Samples were collected from cabbage cultivations dry (Anuradhapura), wet (Kandy), intermediate (Badulla) zones Sri Lanka during 2017-2019. Bioassays conducted five insecticides using leaf dip method. Biochemical assays examined activity insecticide detoxifying enzymes insensitivity organophosphate/carbamate target site, acetylcholinesterases (AChEs) Badulla Kandy A 636 bp mtCOI gene sequence used infer phylogeny. spectrum populations low moderate; 17-25% thiamethoxam, 11-15% acetamiprid, 20-28 % carbosulfan, 20-41 etofenprox, 4-9 profenofos. Elevated esterases (specific activities 0.91-1.11 μmol/min/mg protein) glutathione S-transferases (1.27-1.82 observed for increased metabolism Monooxygenase-based detoxification noticeable neonicotinoid resistance. Insensitive AChEs contribute organophosphate carbamate Phylogenetic analysis revealed that 2 haplotypes studied are present three tested, indicating environmental biological pressure, including selection may be contributing emergence novel genotypes