Production of polyhedrin monoclonal antibodies for distinguishing two Orgyia pseudotsugata baculoviruses

Monoclonal antibodies were produced to polyhedrins from Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV) and single-capsid nuclear polyhedrosis virus (OpSNPV). Although the polyhedrins are closely related, antibodies were selected which allowed differentiation between the two viruses. In an indirect enzyme-linked immunosorbent assay, purified OpMNPV and OpSNPV polyhedrins could be detected by specific monoclonal antibodies at concentrations as low as 2 and 5 ng/ml, respectively. The antibodies were also capable of identifying their homologous polyhedrin in extracts of infected insects. These antibodies would be useful for monitoring production of the viral insecticide, TM Biocontrol-1, which by license must contain only OpMNPV, and to confirm that insect mortality after aerial spraying with this insecticide is attributable to OpMNPV infection.