Invasion of a nuclear polyhedrosis virus in midgut of the armyworm, Pseudaletia unipuncta, and the enhancement of a synergistic enzyme

A synergistic enzyme, extracted from the capsule of a granulosis virus, enhances the infection of a nuclear polyhedrosis virus (NPV) of the armyworm, Pseudaletia unipuncta. Since many small polyhedra and virus bundles penetrated through the peritrophic membrane of the midgut in the absence and in the presence of the enzyme, the site of action of the enzyme appears to be the cell membrane of the midgut cells. Four hours after the feeding of the NPV, more nucleocapsids were found in midgut cells of larvae treated with the enzyme than in those of untreated larvae. The mode of attachment and invasion of the NPV into the midgut cells are essentially the same as reported previously by other workers.