Characterization of an iridovirus isolated from the southern mole cricket,Scapteriscus vicinus

A new iridovirus has been detected from diseased southern mole crickets, Scapteriscus acletus, collected in Brazil during the spring of 1986. This icosahedral virus measuring 146 nm (side-side) to 172 nm (apex-apex) has been purified via Ficoll gradient centrifugation and demonstrated to be infectious to 1st instar Scapteriscus vicinus nymphs. The cytopathology of this virus is typical of the pattern documented for other iridovirus isolates. Characterization of the structural polypeptides by SDS-polyacrylamide gel electrophoresis revealed an array of 3 major and 17 minor polypeptides ranging in molecular weight from 15.1 to 152.0 kDa. Electrophoresis in agarose gels of purified DNA revealed a single band of high molecular weight. Analysis of various restriction endonuclease (REN) digests of this DNA demonstrated it to have an approximate molecular weight of 144 kilobase pairs. Based on differences in the polypeptide profile and REN profiles we believe this virus is distinct from previously characterized invertebrate iridovirus isolates.