Genomic analysis of coconut rhinoceros beetle and its biocontrol agent Oryctes rhinoceros nudivirus

Poster presentation XXIII International Congressof Genetics- abstract:

GENOMIC ANALYSIS OF COCONUT RHINOCEROS BEETLE AND ITS BIOCONTROL AGENT ORYCTES RHINOCEROS NUDIVIRUS

Coconut Rhinoceros Beetle (CRB, Oryctes rhinoceros) is an introduced pest species of coconut palms in the Pacific. Oryctes rhinoceros Nudivirus (OrNV) was introduced in the 1960s as a biocontrol agent for CRB. Following a very effective period of control there are now variants of CRB that are no longer affected by OrNV. We are using different approaches to understand this phenomenon. To follow the ongoing spread of CRB and the emergence of ‘resistance’ to OrNV, we have initiated a study on the genetic diversity of the CRB across the Pacific using Genotyping-by-Sequencing; are there CRB genotypes that are more susceptible to OrNV and/or more successful in establishing and spreading? In addition we are studying OrNV strains, originally identified in the CRB native range (Asia); are different strains of OrNV more effective biocontrol agents? Recently, based on the genome sequences we generated of six OrNV strains, we have developed a rapid assay to perform OrNV strain identification. This uses multiple OrNV amplicons in a multiplexed analysis across barcoded samples and Oxford Nanopore Technologies sequencing. This allows us to determine the efficacy of different OrNV strains in biocontrol assays where OrNV preparations are fed to CRB in the laboratory and in field settings. In addition it enables the detection and identification of OrNV strains in samples collected from the field in order to understand the presence and spread of strains across the region. The combined understanding of the diversity of CRB and OrNV contributes to improving management of CRB.