[Stock Control 20 Jan 2011]--BIOCONTROL agents have become the quiet achievers in a 10-year national project to control Salvation Jane. SARDI project officer Susan Ivory said that in 1984 it was estimated that Salvation Jane had infested 3.99 million hectares in South Australia. “The annual net cost of controlling Salvation Jane or Patterson’s curse in South Australia has been estimated at $2.3 million,” she said. “Classical biological control was considered one of the best ways forward and the search for effective and host specific agents began.” In 1995 SARDI joined a national project with CSIRO and agricultural departments in Victoria, New South Wales and Western Australia to rear, distribute and monitor biological control agents for the control of Salvation Jane.
The Salvation Jane biocontrol program received strong support and funding from Australian Wool Innovation and Meat & Livestock Australia.
In 1995, the first agent, the crown weevil was released by SARDI Entomology’s Ken Henry. By 2005, five biocontrol agents were in use in South Australia: the leaf mining moth, the crown weevil, the root weevil, the flea beetle, and the pollen beetle.
In the last year of the project Susan Ivory and Ken Henry undertook 105 releases using insects mainly sourced from South Australian field sites.
“It’s such a great feeling when you can go from a few releases sourced in the lab or interstate to collecting thousands of insects with 10 to 30 enthusiastic people from all around the state,” said Susan.
“A great thing about this project is that it took a community approach to achieve the successful distribution of the biocontrol agents. Everyone was on board CSIRO federally, SARDI Entomology at the state level, the regional Animal and Plant Control Boards (APCB) and local individuals and community groups.
“Many people were trained to field collect, redistribute and monitor biocontrol agents; especially the APCB officers. This knowledge is now embedded in the community and the NRM Boards.”
SARDI data provided the key to the success of the project. It told the team what agents were working best under the different geographic and climatic conditions, and when sites were ready and the agents established sufficiently to become repositories for future field collection and distribution.
“Biocontrol is a long-term option for controlling weeds. In some cases it can take up to 30 years for populations of the agents to be sufficiently high across the landscape for effective suppression to occur,” said Susan.
“In 2010, in what should have been a year with rampant growth of Salvation Jane, there were very few fields of purple in the Adelaide Hills. This is being attributed to the biocontrol agents having strongly contributed to this change.
“It’s not until years after all the hard work has been done that you can actually see the benefits of a biocontrol program. And for many people it’s such a gradual change that it’s not until you see the old photos or hear the stories that you recognise the change. The biocontrol agents really are the classic quiet achievers.”
A 2006 report for the CRC for Australian Weed Management found that in general biological control programs provide a return on investment of $23.10 for every $1 invested. The same report found that the national Salvation Jane biocontrol program had a return on investment of 52:1.
The lessons learned and the networks made are now used in new weed biocontrol programs for boneseed, blackberry, gorse, horehound, English and Montpellier brooms in a national project funded by the Australian Government under the Caring for our Country initiative.
