Abstract: Recently some codling moth, Cydia pomonella, populations in Europe developedresistance to CpGV. In order to prepare for the possibility of a similar occurrence with the falsecodling moth, Thaumatotibia leucotreta, in South Africa, a search was conducted for novelCrleGV isolates. Through overcrowding, outbreaks of novel isolates were recorded fromlaboratory populations of five geographically distinct host populations. The genetic novelty ofthese and two commercially available isolates was confirmed through restriction enzyme analysisand sequence analysis of the granulin and egt genes. Phylogenetic analysis showed the existenceof two CrleGV-SA genome types. Significant differences in virulence were also shown betweencertain isolates against certain host populations.