Relative pathogenicity of nuclear polyhedrosis viruses from Mamestra brassicae, Euxoa messoria, Agrotis segetum, Autographa california, and Heliothis spp. for larvae of Euxoa scandens (Lepidoptera:Noctuidae)

Abstract Laboratory studies demonstrated that neonate larvae of the white cutworm, Euxoa scandens , are susceptible to infection with nuclear polyhedrosis viruses of Mamestra brassicae (MbNPV), Euxoa messoria (EmNPV), Agrotis segetum (AsNPV), and Autographa californica (AcNPV). Among these viruses, MbNPV and EmNPV were found to be the most virulent and AcNPV the least virulent. Comparative LC 50 values of MbNPV, EmNPV, AsNPV, and AcNPV were 21, 25, 45, and 1075 polyhedra/mm 2 of diet, respectively. The difference between the LC 50 values of MbNPV and EmNPV was not significant. The Heliothis NPV was found to be nonvirulent to all E. scandens larvae. Restriction endonuclease analysis of viral DNAs before and after passage through E. scandens larvae confirm that true cross-transmission occurred.