Examination of population genetics of the Coconut Rhinoceros Beetle (Oryctes rhinoceros) and the incidence of its biocontrol agent (Oryctes rhinoceros nudivirus) in the South Pacific Islands

•We found 3 major mitochondrial lineages (CRB-G, CRB-PNG & CRB-S in the South Pacific.•The GBS data provided evidence for gene flow & admixture between different haplotypes.•We detected high incidence of OrNV infection in all three haplotypes in the region.•The mitochondrial lineages are not an accurate reflection of the dispersal history.•The CoxI based method is not a reliable diagnostic marker for phenotypic traits.