Effects of PropagatingAutographa californicaNuclear Polyhedrosis Virus and ItsTrichoplusia niVariant in Different Hosts12

Abstract

When polyhedra of Autographa californica passaged several times in Spodoptera exigua were passaged in Trichoplusia ni , the size of the polyhedra increased considerably. In addition, these polyhedra contained more virions per cross section of polyhedral inclusion body (PIB), contained a greater mean and mode of nucleocapsids per virion, and were more virulent to neonate T. ni . The polyhedra of T. ni after several passages in T. ni were not altered in size when passaged in S. exigua . However, these polyhedra had more virions per cross section of PIB, had a greater mean and mode of nucleocapsids per virion, and were more virulent to neonate T. ni than were PIBs of T. ni produced in T. ni larvae.