Characterization of a highly mexican virulent strain of baculovirus against fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

Spodoptera frugiperda is the most important pest in corn production, causing economic losses. A new strain of baculovirus, isolated from the fall armyworm S. frugiperda in the State of Guanajuato, Mexico, called SfNPV-Gto, was characterized at both the biological and molecular levels. Restriction fragment patterns were generated, and a phylogenetic analysis was performed between the SfNPV-Gto strain and other SfNPV strains using the conserved genes polh, lef-8, and lef-9. This strain was located within the group of Alphabaculoviruses of S. frugiperda, located in the same clade as the Mexican native strains SfNPV-An1, SfNPVAn2, SfNPV-B, and the exotic strains SfNPV-Ho and SfNPV-Ar. No significant differences were observed at the structural proteins of the occlusion bodies (OB´s) of the SfNPV strains studied. The lethal media concentration (LC₅₀) was determined at a value of 4.1x10³ OB´s/mL, showing it to be highly virulent towards S. frugiperda. The SfNPV-Gto strain turned out to be a new strain never reported before, and due to its high level of virulence, it has high potential for controlling fall armyworms at the laboratory and field levels.