Browsing by Author "Braithwaite, K"

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Barcoding a tool to assist the industry to manage insect incursions
(ASSCT, 2015) Braithwaite, K; Chandler, K; Sallam, N
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.
Genetic diversity among populations of soldier flies : ASSCT poster paper
(ASSCT, 2019) Braithwaite, K; Lindsay, K; Jennings, J
Soldier flies are a serious pest in several regions of the industry. Because they were often considered a localised problem, their impact has largely gone unrecognised. However, in recent years there has been a concerted research effort to gain more understanding of the biology of the pest and to develop better management solutions.
Preparing the Australian sugar industry for exotic disease threats: final report 2009/033
(Sugar Research Australia Limited, 2015) Magarey, R; Samson, P; Braithwaite, K; Thompson, N; Sallam, N
Previous field resistance trial data for downy mildew, Ramu stunt and Sesamia grisescens collected in PNG since the mid-1980s were accessed, analysed and information used as a foundation for project field resistance screening research. 2. Pot methods for moth borer resistance screening were reviewed, a visit to South Africa was made to view pot trial methodology and rapid test resistance screening research plans developed. 3. Field resistance screening trials for the moth borers (Sesamia grisescens and Scirpophaga excerptalis) and the diseases (downy mildew, (Peronosclerospora spp.) and Ramu stunt (tenuivirus)) showed promise in project research. Data collected has been analysed and resistance ratings for Australian commercial varieties assigned and loaded into SPIDNet. 4. A rapid resistance screen for the moth borers (manual infestation of test plants) and downy mildew (using oospores mixed into potting soil) show promise, but each method requires further refinement. 5. The causal agent of Ramu stunt was confirmed as a tenuivirus and a diagnostic assay validated. Suspect disease specimens can now be confidently assayed, should an Australian incursion occur. Some pathogen variation was noted around PNG; it is unknown if this will affect varietal resistance reactions. 6. Molecular tools for assaying for downy mildew were also developed; suspect disease specimens for DM can also now be confidently assayed. Significant DM pathogen variation in PNG was noted, with three taxa identified. One of these may be a new Peronosclerospora species. 7. The project has led to major steps forward in relation to knowledge of these pests and diseases. Our capacity to identify, manage and advise the Australian sugarcane industry with regard to PNG pests and diseases has improved greatly. The industry is now in a strong position to deal with the major pest and disease threats present in PNG.