The nucleopolyhedrovirus of Spodoptera exigua (Lepidoptera: Noctuidae) as a biopesticide: analysis of recent advances in Spain

The greenhouses of Almeria, Spain, represent the largest extension of covered crops in Europe. Larvae of Spodoptera exigua are an important pest in many of these crops and have developed resistance to the majority of insecticides registered in Europe. The nucleopolyhedrovirus (SeMNPV; Baculoviridae) of S. exigua is a native pathogen of this insect. The persistence of the virus is high in the soil of all crops, although its incidence is highest in spring and summer. As many as nine genotypic variants of the virus have been identified in this zone. In terms of pathogenicity, virulence and production of progeny virus occlusion bodies (OBs), mixtures of certain genotypes have greater insecticidal Potential than pure genotypes. Production of OBs in vivo can be Lip to three-fold greater in larvae treated with juvenile hormone analogues. Compounds derived from stilbene have a synergistic activity with OBs ill the laboratory and reduce the lethal dosis in the field. The field efficacy of a simple formulation was greater than that offered by treatments of various synthetic insecticides. The virus is currently being mass-produced in a commercial production facility and the process of registration has begun for its use in sweet pepper crops in Almerian greenhouses. The results of these investigations Should facilitate the development of SeMNPV as a biological insecticide in other parts of the world. including Latin America.