Prevalence of “R” strain and molecular diversity of fall army worm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in India

Abstract

The fall army worm (FAW) Spodoptera frugiperda (J.E. Smith) is an invasive pest native to Americas, and it has recently been observed invasive to India. The mtCOI based analysis of the populations of FAW from the Americas showed the prevalence of two strains viz. “R” (Rice) and “C” (Corn). Recent studies on FAW populations from Africa revealed the predominance of “R” strain that feed primarily on maize. To understand the prevalence of strain and molecular diversity of FAW in India, studies were made on the populations collected on maize, sweet corn, and sorghum from six states of India (Karnataka, Tamil Nadu, Andhra Pradesh, Telangana, Madhya Pradesh and Maharashtra). The results reveal that this is the first report of the occurrence of FAW from Andhra Pradesh, Madhya Pradesh, Maharashtra, Tamil Nadu and Telangana. Further, mtCOI (5′) based sequence analyses revealed that these populations from India aligned with “R” strain with minimal genetic diversity exhibiting no host/location specific variations. FAW populations in India primarily feed on maize as observed in Africa with no incidence on rice yet. The present study suggests a possible invasion by single genetic stock of FAW in India which requires haplotype analysis.