Grey weevil, Myllocerus viridanus (Fabricius) is a polyphagous pest with a wide range of host plants. The pest is reported to cause damage to plants of agriculture and horticulture importance. Taxonomic identification plays a crucial role in designing the accurate management procedures against insect pests. Inaccurate identification often may form a hurdle in implementation of proper management strategies. This work utilizes the advancement in the field of molecular systematics such as DNA barcoding for tracing the phylogeny of the weevil pest by the partial sequencing of mitochondrial cytochrome oxidase I (CO I). The species discrimination studies based on DNA barcoding involved steps like DNA isolation and PCR amplification. Evolutionary analysis was carried out in Mega 7 software. GenBank deposition indicated the novel and first time records of M.viridanus and was provided with accession numbers KU871376&MG021103 Further analysis showed that M.viridanus has 96% similarity with M.undecimpustulatus (KX778624) and 85%. The translational product of aligned data showed a difference in two amino acid sequences between M.viridanus and M.undecimpustulatus. The nucleotide sequences with 96-84% similarity were retrieved from NCBI and included in the study. The protein translation yielded a short chain of 219 amino acids. This approach was very informative and it helped in the better understanding of genetic variation among closely related species.
