Australians wage war on national environmental pest

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Weeds Cooperative Research Centre (CRC) announced on 9 August that they had released the rust fungus, Puccinia myrsiphylli, in a bid to stop the uncontrollable spread of the weed they describe as ‘an environmental curse’ – bridal creeper, Asparagus asparagoides.

“We can’t place a dollar value on the devastation that this weed is causing to our natural environment, but it is capable of wiping out native species” Dr Mark Lonsdale, leader of the CSIRO Entomology Weed Management Program said. Bridal creeper is running amok in every state across southern Australia, where researchers will concentrate their efforts against the ornamental plant, originally introduced from South Africa in the 1850s.

The rust fungus has been tested in quarantine facilities and 21 organisations have been involved in the approval process to ensure that it is safe for release. “The pathogens used for biological control have a history of being very specific and often devastating against the target plant,” Dr Morin, the Weeds CRC/CSIRO pathologist in charge of the project said. The rust attacks the cells of the leaves and severe infection causes the plant to loose its foliage causing the plant to use its reserves stored in underground tubers. “It is these mats of tubers that prevent plants from germinating and allow bridal creeper to completely smother other plant species” Morin said.

The National release of the rust was made by the Australian Minister for the Environment and Heritage, Senator Robert Hill at the Botanic Gardens in Adelaide, South Australia. CSIRO has made releases in New South Wales and Western Australia, and State departments in Southern Australia will continue to make further releases as the rust becomes established. Early release sites will be monitored to determine the rate of infection and spread by the fungus and the impact it is having on bridal creeper.

This was the second biological control agent to be released on bridal creeper in a project that has been funded by the Cooperative Research Centre for Weed Management Systems and the National Parks and Wildlife Services in Southern States through Australian and New Zealand Environment and Conservation Council (ANZECC). The first agent, released in May 1999, was the bridal creeper leaf hopper, Zygina sp. The combined effect of the two plants is expected to make a major dent in the incidence of bridal creeper.