Australia’s grape and wine sector faces a serious threat from Xylella fastidiosa, a highly destructive plant bacterium that has devastated vineyards and horticultural crops overseas. Although not present in Australia, proactive research and strong biosecurity measures are essential to keeping this bacterium out. Xylella, also known as Pierce’s Disease in grapevines, affects more than 700 plant species, including native, commercial and ornamental plants. It has no known cure and is considered Australia’s most threatening exotic plant disease.
“This is not just a viticulture issue, it’s a national concern,” said Dr Jo Luck, Program Director at the Plant Biosecurity Research Initiative (PBRI). “If introduced, Xylella could cost the grape and wine sector alone up to $7.9 billion, according to ABARES. The potential impact on horticulture and native ecosystems would be just as devastating.”
Symptoms of infection include scorched or browning leaves, stunted shoots, reduced fruit size, dieback, and vine death within a few years. The disease spreads through infected plant material and is transmitted by sap-sucking insects such as spittlebugs and sharpshooters.
To help prevent an incursion, Australia introduced emergency biosecurity measures in 2015. These include offshore testing and certification of nursery stock and plant material from regions where Xylella occurs, to ensure imports are disease-free.
Although the key insect vectors responsible for spreading Xylella overseas are not found in Australia, several native spittlebug and leafhopper species might have the potential to act as local vectors.
To better understand this risk, Wine Australia, Hort Innovation and the Australian Government, through the Plant Biosecurity Research Initiative (PBRI) and the Department of Agriculture, Fisheries and Forestry (DAFF), co-funded a three-year research project led by Agriculture Victoria.
Dr Mark Blacket, Senior Research Scientist at Agriculture Victoria, said the project aimed to identify and improve our understanding of potential native insect vectors of Xylella near host crops, including grapevines, and monitor their population dynamics across southeastern Australia.
The research found that if a Xylella incursion occurred, the native spittlebug Bathyllus albicinctus may pose a relatively high risk as a potential vector due to its wide geographic distribution, broad host plant range, feeding behaviour and seasonal population peaks.
“These findings are critical,” said Robyn Dixon, Program Manager for Biosecurity, Pest & Disease at Wine Australia. “They give us a head start in understanding how Xylella could spread if introduced and help us design effective surveillance and response strategies.”
What growers can do
“Protecting our vineyards from Xylella fastidiosa starts with awareness and preparedness,” Ms Dixon said. “Growers play a key role in frontline defence.”
Here’s how growers can help:
- Know the signs: Be aware of disease symptoms like leaf scorch, dieback and fruit loss.
- Monitor plant health: Regularly inspect your vineyard for unusual symptoms or changes.
- Understand the risks: Learn about potential insect vectors and how they behave.
- Practise good hygiene: Clean tools, equipment and vehicles to prevent spread of pests and diseases.
- Report suspicious symptoms: Contact your state or territory agriculture agency via the Exotic Plant Pest Hotline on 1800 084 881.
“Simple actions taken early can make a big difference in keeping this devastating disease out of our vineyards,” Ms Dixon added. “Wine Australia continues to work closely with DAFF and the PBRI to support critical research and preparedness initiatives.”
Learn more
• Familiarise yourself with the symptoms of Xylella fastidiosa and watch this short video
• Read the full final report from Agriculture Victoria Research
• Learn more about the nationally agreed approach to improve the way we prepare for, detect and respond to Xylella in the National Xylella Action Plan
Image: Grapevine leaf infected with Xylella fastidiosa – Pierce’s Disease. Image: Pragya Kant, Agriculture Victoria Research