----- forwarded message ----- Date: Fri, 23 Jul 2004 01:25:04 -0400 From: [EMAIL PROTECTED] Subject: Bogong moth plays arsenic detective
Bogong moth plays arsenic detective Monday, 19 July 2004 Judy Skatssoon ABC Science Online Genetic analysis of bogong moths may lead scientists to agricultural lands contaminated by arsenic, a conference has heard. Australian researcher Dr Neil Murray from La Trobe University presented his work to the recent annual scientific meeting of the Genetics Society of Australia. Scientists have known for several years that this native moth (Agrotis infusa) had become a reservoir of high concentrations of arsenic, as its larvae had fed in areas sprayed with pesticides. And dead moths were in turn poisoning vegetation in the Snowy Mountains in New South Wales and the Victorian Alps where they 'hibernate' or aestivate over summer. Analysis of droppings from native animals showed that arsenic was also being passed onto alpine species that fed on the moths, including the endangered mountain pygmy possum. Scientists worked out that the moths were coming into contact with the arsenic in lowland areas where larvae fed during the breeding season. Suspect areas included cotton-growing parts of the lower Murray River area in New South Wales as well as around Swan Hill in Victoria, and southern Queensland. But because some moths were contaminated and others were clean, the actual source of the arsenic remained a mystery. For the past three years Murray and his colleagues have been analysing the DNA of bogong moths so they can match gene sequences from contaminated moths to lowland larvae. "If we can get genetic markers we might be able to find out exactly where the arsenic's coming from without digging up every cubic metre of soil in western Victoria and New South Wales," Murray said. "The genetic marker approach to tracking populations is far more efficient than trying to track moths." Murray said the arsenic could be the remains of past herbicides or pesticides use. For example, arsenic was widely used to poison prickly pear before the introduction of the cactoblastis moth in 1925. Bogong moths were now providing long-distance transport for residues, Murray said. "It's one of these quite terrifying things how agricultural management in ecosystems out there is having an impact on ecosystems hundreds of thousands of kilometres away," he said. Murray said his work was complicated by the fact that analysis of the moths' mitochondrial DNA showed very little genetic variation. This was probably because bogong moths were highly efficient and genetic mutants were unlikely to survive, he said. http://www.abc.net.au/science/news/stories/s1154836.htm posted by Deborah Elaine Barrie 4 Catherine Street Smiths Falls, On Canada K7A 3Z8 (613)284-8259 [EMAIL PROTECTED] http://www.noccawood.ca subscribe to list service at website
