A comparative study of different types of viruses and their capsules in the polyhedroses and granuloses of insects

Abstract

It has recently been shown (Smith & Wyckoff, 1950) that, in addition to the classical type of nuclear polyhedral disease of lepidopterous larvae, there exists a second type of polyhedrosis with spherical virus particles instead of rods. This was demonstrated in the case of two tiger-moth larvae,Arctia villicaandA. caja. The polyhedra of this type of disease do not dissolve fully when treated with weak alkali but leave behind a honeycomb-like shell pitted with round holes. We have also shown (Xeros, 1952, Smith & Xeros, 1953a) that in all our material these polyhedra occur in the cytoplasm and not in the nuclei and are confined to the cells of the midgut.