Barcoding a tool to assist the industry to manage insect incursions

Abstract

THE AUSTRALIAN SUGARCANE industry has been fortunate not to have several significant insect pests that exist overseas. Moth borers are a particular concern to the Australian sugar industry due to the heavy losses they cause overseas and their potential to colonise new regions. Other high risk exotic pests include whiteflies, planthoppers and aphids. The biosecurity group in SRA is involved in many activities to prepare for possible incursions, including the development of diagnostic methods. Since the adult stage (which is required for correct taxonomic identification) may not be present in the early stage of an incursion, it is important to develop diagnostic techniques which apply to all insect stages or any available field material. The presence of frass may be the only indication that stalk damage is due to a moth borer. In such cases, identification can be greatly assisted by DNA-based techniques. For almost all animals, the universal barcode is the cytochrome oxidase I gene (COI), and this universality has led to the Barcode of Life, a project to promote DNA barcoding as a global standard for sequence-based identification. As several important exotic pests do not have publically available barcodes, SRA is assembling its own reference collection. Using the minor Australian sugarcane pest Bathytricha truncata as an experimental system, we attempted to develop methods to extract DNA and perform barcoding on frass. The method was then applied to detect three exotic borers in stalk material from PNG. Accurate detection of insect DNA from the complex stalk/frass environment is challenging, but can be achieved.