Ground Cover Supplement : GC Supplement - Biosecurity
GROUND COVER BIOSECURITY 14 DIAGNOSTICS & PRE-BREEDING WHILE THE ONE known incidence of Khapra beetle (Trogoderma granarium) in Australia was quickly eradicated, identification of this voracious exotic pest can be tricky. First, they eat almost anything -- grains, spices, herbs, dried fruit, meat and wool -- so they can survive in many products and in packaging. They can even survive for years without eating at all, which means empty containers could house a healthy population of Khapra beetle that only invade if the content is edible. Second, Khapra beetle identification is more reliable based on adults rather than larvae. However, the trouble is that the Khapra beetle spends more than 95 per cent of its life in the larval form; and if that does not present enough difficulties, the larvae usually eat the dead adults so in most cases only bits can be found. In addition, as the insects move around, the grain acts like sandpaper, rubbing off the beetle's hairy cover. So even if adults are present, the beetle loses many of its identifying features. Finally, there are many members of the Trogoderma genus. So while Khapra beetle is a threat to the grains industry, there are 52 described and relatively harmless Trogoderma species that are endemic to Australia and an estimated 50 waiting to be discovered and described. Misdiagnosis poses just as much of a threat through the imposition of trade barriers, due to erroneously declaring Australia a Khapra beetle country. To help improve accurate and rapid identification of Khapra beetle, entomologists at the Department of Agriculture and Food, Western Australia, have been working on a Cooperative Research Centre for National Plant Biosecurity (CRCNPB) project. There are three elements to the project: ndeveloping protocols for DNA identification of different Trogoderma species; n establishing a national Trogoderma laboratory; and ncreating an international Trogoderma reference collection. The overall aim of the project is to protect Australia's valuable grain export market by identifying unwanted Trogoderma visitors as quickly as possible to facilitate eradication. Another aim is to distinguish the exotic pest species from the similar native but non-destructive species that are found occasionally in grain leaving our shores. Mark Castalanelli has been working on the new DNA protocols for the CRCNPB as part of his PhD project, through Curtin University of Technology's WA Biomedical Research Institute. The extraction technique he has developed allows DNA to be taken without physical damage to the specimen, leaving it intact for morphological study. In the past, it had to be crushed and ground to extract DNA, making visual identification impossible. DNA identification needs to be supported by morphological identification. Both techniques are equally important in the positive identification of an intercepted beetle sample. There is still a considerable amount of work to be done as the protocol needs to be verified by independent laboratories; it is already being evaluated by the US Department of Agriculture. Following its successful acceptance, the protocol may be included in the international Khapra beetle identification protocol. World-first The establishment of a national Trogoderma laboratory and international reference collection will be the first facility of its kind in the world. The new diagnostics laboratory will be world- leading, tapping into a suite of tools, many of them developed as part of the CRCNPB. Tools will include DNA screening with non-destructive DNA-extraction methods and imaging using photomontage and the web- based Pests and Diseases Image Library (PaDIL) and Lucid Keys (a computer-based identification system). Building the international reference collection of Trogoderma specimens is the work of entomologist and Trogoderma specialist Andy Szito. He is visiting collections around the world and has examined thousands of specimens. Mr Szito has morphologically identified more than 100 Trogoderma species, which will back up the DNA profiles. Locally, the first national Trogoderma trapping program is complete, with pests trapped at 64 grain-storage sites around Australia. The samples will be the basis of taxonomic studies and the development of DNA markers of native and non- native storage pest Dermestids, including a closely related but less serious pest, the warehouse beetle. The trapping program will also establish the biogeographic diversity of the different species. □ GRDC Research Code NPB00005 More information: Dr Oonagh Byrne, molecular diagnostics laboratory manager (Trogoderma), DAFWA, 08 9368 3600, email@example.com; www.grdc.com.au/NPB00005 Establishment of Khapra beetle in Australia could cost the grains industry at least $500 million annually in trade restrictions. COORDINATED APPROACH TO VORACIOUS BEETLE Khapra beetle is one of the world's most damaging pests of stored grain, but identification is not at all simple By Oonagh Byrne MISDIAGNOSIS POSES JUST AS MUCH OF A THREAT TO BIOSECURITY AS THE ACTUAL PRESENCE OF A PEST.
GC Supplement - Capacity building
GC Supplement - Grain storage