Abstract
A virus with morphological and physicochemical properties similar to those of the vertebrate caliciviruses was isolated from navel orangeworms, Amyelois transitella (Walker). Infected larvae contained two types of virus particles: a 185S, 38 nm cupped particle (ACSVi) with a single major polypeptide of 70000 mol. wt. and a 165S, 28 nm smooth particle (ACSVii) with a single major polypeptide of 29000 mol. wt. Larval frass contained a heterogeneous population of virus particles. Evidence is presented which suggests that the 38 nm particle degrades by proteolytic digestion to produce predominantly 28 nm particles in frass. Virus particles contained a single-stranded RNA of 36S (about 2.5 x 106 mol. wt.).