| Popis: |
An isolate of the gypsy moth, Porthetria (Lymantria) dispar, nuclear polyhedrosis virus infected larvae of the tobacco hornworm, Manduca sexta, when it was fed to first instar (neonate) individuals. The virus caused unusually heavy proliferation of cytoplasmic polyhedra in the midgut cells very soon after larvae began feeding and growth was markedly reduced. However, noticeable mortality did not occur until after 25 days when most of the control larvae had begun to pupate. About 65% of the treated larvae had died by day 31 and none had pupated. Electron micrographs showed both cytoplasmic and nuclear polyhedrosis virions in diseased larvae. Those in nuclei were rod-shaped (baculovirus) and they were sparsely distributed. Polyhedra in these nuclei were often poorly formed or absent. |
