Abstract
Larvae of the pine emperor moth, Nudaurelia cytherea capensis, naturally infected with Nudaurelia virus (NV), contained a second serologically unrelated virus which we have called Nudaurelia ω virus (NωV). NωV had a buoyant density of 1.285 g/ml in CsCl and yielded a single major polypeptide of 65000 daltons on gel electrophoresis. The particles of NωV were morphologically distinguishable from those of Nudaurelia viruses described by others, and tryptic peptide analyses indicated that NωV protein was distinct from that of NV and NV. Both NωV and NV contained a small stable fraction of particles with buoyant densities of about 1.33 g/ml.