Molecular Characterization of Fall Armyworm (Spodoptera frugiperda, J.E. Smith) Feeding on Rice (Oryza sativa L.) in Tamil Nadu

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an invasive insect pest of India native to the Western Hemisphere. The pest damages more than 350 plant species. FAW is genetically divided into two strains viz. corn (C) strain which feeds mostly on maize, sorghum, etc. and the other is a rice (R) strain that prefers rice and other small grasses. In the present study, fall armyworm samples were collected from rice crop in two different places of Tamil Nadu, India during 2019-20 and strain identity was confirmed. Polymerase Chain Reaction (PCR)- Restriction Fragment Length Polymorphism (RFLP) profile of mitochondrial cytochrome oxidase subunit I fragment confirmed the presence of both ‘R’ and ‘C’ strains of FAW in rice crop. Nucleotide variations were observed from PBS, TNAU isolate at five places and two places in Killikulam isolate. Phylogenetic analysis revealed that PBS, TNAU isolate ON247930 (C strain) has completely diverged from Killikulam isolate OM491244 (R strain).