Warrnambool welcomes the Weed Warriors Program in its fight against environmental weeds. Weed Warriors is a national program which promotes weed control through environmental education and awareness, highlighting the impact weeds has on Australia’s native flora and fauna. The Warrnambool Coastcare Landcare Group has created a partnership with the DPI and the Keith Turnbull Institute, the Warrnambool City Council and South West Tafe and up to 5 schools, involving over 500 students have benefited from the Program since 2006. It also won the 2007 Victorian Weedbuster Award.
The Warrnambool Weed Warriors Program is targeting the spread of the Bridal Creeper Asparagus asparagoides in the South Warrnambool Wetlands. The main goals of the program are to contain the spread of the Bridal Creeper in this area, reducing the threat on valuable native habitat and also to raise community awareness of environmental weeds and their impact on biodiversity. In the case of the South Warrnambool Wetlands the Bridal creeper is smothering coastal vegetation and threatening to further encroach on the fringe of the wetland which contains the Beaded glasswort Sarcocornia quinqueflora, a food source for the rare migratory Orange Bellied Parrot Neophema chrysogaster.
The Bridal Creeper is a South Africa vine and was brought to Australia as a garden ornamental plant in the 1850’s. Today the garden escapee has found its way into Australia’s natural environment with drastic impacts on natural ecosystems. The plant forms a thick mat of underground tubers which impedes root growth from other species as well as the dense choking coverage over the canopy of other species. The bridal creeper flowers in September and sets fruit in October with seeds staying viable in the soil for three years and each year of growth, the vines underground tubers multiply and store food reserves. Due to its abilities to grow quickly and climb existing plants, the bridal
creeper smothers and out competes native vegetation for light, water and nutrients. It alters natural ecosystems to the extent that it has been declared a Weed of National Significance.
With the help of a Bush Guardians Grants through the Department of Sustainability and Environment (DSE) from 2007- 2008, we have been able to employ a project coordinator to manage the Warrnambool Weed Warriors Program. The program involves getting school students to be actively involved in the management of the Bridal Creeper problem through the breading of biological control agents in the classroom environment through to the release and monitoring stages. Schools are provided with their own “mini research lab” in the form of a Perspex cage, to breed the little leaf hoppers over a six week period.
Effective management of bridal creeper using chemical or mechanical management is expensive and time consuming (some Shires use Helicopters) These control methods were not considered to be feasible on the Merri Wetland site. The size of the infestation and inaccessibility of areas within the wetland favour this form of attack. Using biological control as a management tool doesn’t erradicate the weed completely, but reduces the spread and density by reducing biomass and seed production.
Is it Safe?
The Biological controls for the Bridal Creeper are the Leafhopper Zygina sp. and the Rust Fungus Puccinia myrsphylli. They have come from their natural environment of South Africa and have been tried and tested in an intensive scientific program developed by the Keith Turnball Research Institute in Frankston to ensure the biological controls causes no threat to the native flora and fauna and humans. AQIS have approved the use of the leaf hopper and rust fungus as biological agents.
How does it work?
Adult Leafhopper Zygina sp. approximately 2.6mm in length
The bridal creeper leafhopper Zygina sp suck the chloryophyl out of bridal creeper leaves only, leaving a distinct white pattern on the surface. The life cycle is completed on the bridal creeper, Adults live from 6 -8 weeks, up to 180 eggs per female and hatch after 2 weeks. The nymphs reach adulthood in 2 weeks. The hoppers reliance on the creeper mean the population declines over summer in conjunction with bridal creeper dieing back.
The rust fungus Puccinia myrsphyllia has a more complicated life cycle with 5 spore stages. It lies dormant over summer on dead bridal creeper and is triggered by low temperature and rain, where infective spores form and are dispersed by wind. The rust appears as yellow wart like marks on the surface of the leaf and orange cup shaped fruiting bodies underneath. The rust reduces the photosynthetic area on the leaf, diverts water and energy away from the plant and depletes the tuber mass.
Currently in 2010, the Merrivale Primary School and Warrnambool East Primary School are involved in the program. This is an exciting hands on project that allows students to see first hand the ability of biological controls to fight against weeds while gaining a greater understanding on the issues of habitat fragmentation and the threat on biodiversity from environmental weeds. It further highlights to the community the threats of garden escapees on our natural ecosystems. Have a look in your garden; are there any environmental weeds that may be the next Bridal Creeper?
Hi, I’m Rebecca Corbett, the new coordinator of the Weed Warriors Program for 2010. Nicole Wood has handed over the reins to me after four successful years of looking after the program. I am happy to report the program is back in action after some hiccups earlier this year. The objective of this program is to involve local students in the use of two biological control methods (little leaf hopping bugs and a rust fungus) to attack the non native weed, the Bridal Creeper. The little leaf-hoppers suck the chlorophyll out of their host plant and the plant slowly dies. This is where I will be presenting and educating the process to two schools. Term two presentation to the students was postponed when a storm wiped out the leaf-hopper population at the quarantine centre in Frankston. In term three the leaf-hopper populations have been re-established and two presentations have been made to grade 5/6 classes at Merrivale Primary and East Warrnambool Primary. Both these classes are currently breeding leaf-hoppers in bridal creeper incubation boxes, in their class rooms. Later in the term, they will release the hoppers onto active bridal creeper in the South Warrnambool Wetlands. At this stage I may ask for some extra volunteer assistance in helping to supervise the children on release day. Hopefully the hoppers will make an impact on this suffocating weed and follow up on Nicole’s previous work. The bridal creeper will be monitored. The children are enthusiastic and learning about biological control, introduced species and plants, the impact of weeds and their local environment. REBECCA