Identification and purification of a granulosis virus found in fall armyworms

Abstract

A virus was found infecting larvae of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) (Smith, 1797), in Sete Lagoas, MG, Brazil. Virus extracts from infected larvae were able to cause up to 100% mortality in three-day old larvae feeding in artificial diet. The identification of the virus, made by electron microscopy, showed that it was a granulosis virus, belonging to the genus Baculovirus and is composed of enveloped nucleocapsids which are occluded in proteinaceous inclusion bodies. Purifications by differential and sucrose gradient centrifugations yielded 22 mg of inclusion bodies per infected larva. Due to its pathogenicity, large number of inclusion bodies per infected larvae and simplicity of purification procedures, the identified virus shows a great potential to be used as a bioinsecticide in the biological control of the fall armyworm.