One of the most harmful pests of Zagros forests is The green oak leaf roller moth, Tortrix viridana. This pest causes heavy damage to oak trees by feeding on the reproductive buds of the trees. The genetic differences in the host plant-associated populations of oak leafroller moths have been assessed in the oak forests of northwestern Iran using the 28s gene. The genetic diversity of collected T. viridana samples fed on the host oak species Quercus branti was investigated using the 28s gene sequence in the northern Zagros region. The samples were collected from the forest area of West Azerbaijan, Lorestan, Kurdistan and Kermanshah provinces. The collected samples were in the larval stage and kept in the laboratory until they turned into pupa and insects. DNA extraction was done by the CTAB method. To amplify the 28s region, the 28s gene sequence of the Tortrix genus from NCBI has been used for primer design. The desired region was amplified using the PCR method, and the PCR products were sequenced. Twenty-one samples were selected to investigate genetic diversity using the 28s gene, and 18 samples with a higher-quality DNA sequence were used for further investigations. DNA sequences were edited using Bioedit software and aligned using MegaX software, and a phylogenetic tree was drawn by the UPGMA method with 1000 sampling repetitions. The results of the phylogenetic tree showed that the different samples of the green oak leaf roller moth have diversity based on geographical distance. Assessment of the genetic structure of the populations showed that higher diversity was demonstrated in intrapopulations than inter-populations geographically.
