Melbourne Water is carrying out works at Cardinia Reservoir to reduce the number of pine trees to stop the spread of a Giant Pine Scale infestation. We are replanting the affected areas with native plants and shrubs. These works will protect Cardinia Reservoir and nearby forests from further damage from giant pine scale and ensure the long-term biodiversity of the area.
Giant pine scale is a tiny scale pest insect that feeds on the sap of pine, fir and spruce trees and spreads by crawling to nearby host trees. Trees infested with giant pine scale display a white wax secretion resembling cotton wool on the trunks and branches. Infested trees will typically dry up and die as a result of the insects feeding on the tree’s sap. Giant pine scale is notoriously very difficult to manage – the insects have no known predators in Australia and there are no effective chemical treatment options available.
Giant pine scale was confirmed in Melbourne for the first time in 2014 and first detected in Cardinia Reservoir in 2017 in approximately 20 trees. Our efforts to contain this spread have had limited impact, with the estimated number of infested trees now at several thousand, covering approximately 40 hectares. We anticipate all of these infested trees would die in the next 5 to 10 years.
There are 44,000 pine trees growing in the Cardinia Reservoir catchment. Removing the trees infested with giant pine scale and those at risk is necessary to halt the current infestation and prevent the broader risk of infestation across the region.
Dying trees are a safety hazard as they increase the available fuel in the event of a bushfire, as well as having the potential to fall on land managers working in the catchment.
Melbourne Water has worked closely with experts including the Department of Environment, Energy and Climate Action (DEECA) to build a Biosecurity Plan for safe treatment and removal of the pine trees. Timber removed from the site which has not been infested is being fumigated off-site and sold for export.
The highest standard of equipment hygiene is being used to avoid spreading giant pine scale further within the catchment or surrounding area. Vehicles working in the catchment are washed with hot water at high pressure as needed which means we do not need to use insecticides or chemicals.
To ensure the long-term biodiversity of Cardinia Reservoir, the affected areas are being revegetated and replanted with 60,000 native plants and shrubs over three years.
There is unlikely to be any direct local impact to people outside the Cardinia Reservoir closed catchment during these works.
There will be some increased vehicle movement around the catchment and possible noise from vehicles and machinery operating on site.
We are using water trucks to bind and protect unsealed road surfaces during dry weather, to prevent the spread of dust and minimise the impact of works to nearby plants and animals.
Visitors and residents may see some areas in the catchment where the works are occurring. These areas where the pine trees are being removed will look bare for a while until the new native plants can develop.
By managing this infestation of giant pine scale, we continue to protect our important catchment forests and supply the community with a safe and reliable water supply, now and for generations to come.
Work commenced in the western areas of the catchment to remove the infestation of giant pine scale
Works commenced in the southern area of the catchment to remove giant pine scale and pine trees at risk to prevent further spread across the catchment and region.
Revegetation and replanting with native plants and shrubs commences.
Proposed completion.
Agriculture Victoria website - Giant pine scale | Priority pest insects and mites | Pest insects and mites | Biosecurity | Agriculture Victoria
Watch the video - Giant pine scale management in Victoria (youtube.com)
Melbourne Water via 131 722 or [email protected]