Histopathology of the cabbage looper, Trichoplusia ni, infected with a nuclear polyhedrosis

Abstract

The histopathology of a nuclear polyhedrosis of the cabbage looper, Trichoplusia ni, infected with four viral preparations was investigated. As previously reported, the nuclei of hypodermis, fat body, tracheal matrix, and blood cells of the cabbage looper showed signs of infection. Polyhedra were also observed in the sarcolemma, neurilemma of nerves, segmental ganglia, subesophageal ganglion, and brain (including some neurones of these nerve tissues), testicular sheath, wing buds, some parts of silk glands and Malpighian tubules, and in connective tissue surrounding the midgut. Infection of midgut epithelium was observed infrequently following treatment with any preparation. Although two types of polyhedra, small and large, predominated in all four virus materials, polyhedra of different grades in size, but always of the same size in the same nucleus, were also observed.