Examination of New Zealand's endemic Wiseana nucleopolyhedrovirus by analysis of the viral polyhedrin gene

Insects of the genus Wiseana (Lepidoptera: Hepialidae) are major agricultur al pes ts in New Zealand. Singly envelop ed nucleopolyhedroviruses (SNPVs) isolated from three of the seven described Wiseana species have potential a s biological control agents. As part of an effort to characterise the Wisea na SNPV genome the polyhedrin gene was cloned and the nucleotide sequence d etermined. The gene sequence was used, in conjunction with morphological an d restriction endonuclease analysis,to compare isolates from different site s and species of Wiseana. Heterogeneity was detected within a single site, as well as between SNPV from separate Wiseana species. The extent of diverg ence between the nucleotide sequences was small enough, however, to conside r three SNPVs from W. signata, W. cervinata and W. umbraculata as different strains of a single SNPV species. This improves the likely practicability of developing a single viral agent to control this pest complex. In additio n, the virus polyhedrin gene sequence was used to estimate the phylogenetic relatedness of a W: signata SNPV to 16 other NPV from diverse insect gener a. These comparisons suggest the Wiseana SNPV was unique within the Baculov iridae, but was more closely related to the group II NPVs.