Giant pine scale
Giant pine scale (Marchalina hellenica) is a scale insect that lives by sucking the sap of pine, fir and spruce trees.
This insect was recorded in Australia for the first time in late 2014, in metropolitan Melbourne and in Adelaide.
Trees impacted by large populations of giant pine scale suffer severe dehydration and dieback of branches, and can eventually die.Plantation foresters, arborists and the general public are encouraged to report any suspected detections of giant pine scale.
Giant pine scale impacts pine, fir and spruce trees and in large populations can kill trees. In Victoria, there are currently 161 properties and over 4,300 infested trees in the south east suburbs of Melbourne.
The municipalities where giant pine scale is found include: Monash, Casey, Yarra Ranges, Cardinia, Kingston, Greater Dandenong and the Mornington Peninsula.
Since January 2015, Agriculture Victoria has been working to protect Australia's $1.16 billion softwood plantation industry from the threat of giant pine scale.
During the response, infested trees in Victoria were chemically treated, but this measure did not work as effectively as expected. Live scale insects still remain on infested trees.
Alternative options were considered, however a national panel has concluded that it is no longer technically feasible to eradicate giant pine scale and Agriculture Victoria is now working on a plan to limit its spread and mitigate its impact.
Agriculture Victoria will continue to work with affected stakeholders and industry to transition to management arrangements that will aim to mitigate the impact of the pest on urban communities and softwood plantation industries. This includes meeting with all affected councils.
What is a restricted area?
Restrictions on the handling and movement or giant pine scale host materials are in place to try to limit the spread of this pest.
In accordance with the Plant Biosecurity Act 2010, a Restricted Area for the management of giant pine scale has been declared.
Declaration of a Restricted Area means that giant pine scale host material must not be removed from the area without a permit. Host material includes plant roots and leaves, mulch, woodchip, soil or any equipment that has been in contact with a host plant or host material.
The Restricted Area prohibits:
- The movement of giant pine scale host material (including wood chips, mulch, branches, cones and needles of pine, fir and spruce trees, and any earth material or used equipment associated with giant pine scale host trees) from the Restricted Area without a permit; and / or
- The pruning or destruction of giant pine scale host trees within the Restricted Area is prohibited without a permit.
The Restricted Area will be reassessed during the development of the transition to management.
The current Restricted Area includes suburbs within the municipalities of Monash, Casey, Yarra Ranges, Cardinia, Knox, Stonnington, Glen Eira, Boroondara, Kingston, Whitehorse and Greater Dandenong. Prior to the latest detection near Tyabb, giant pine scale had only been found in these areas in Victoria.
An interactive web-based application has been developed for property owners and industry to determine whether they are located within a declared restricted area. All you need to do is enter your address and the map will tell you whether there are restrictions in place.
Enter your full street address in the box below and then click the 'Am I Affected?' button.
If your address is displayed within a red, shaded area, you are in the restricted area.
If your address lies within a non-shaded area, you are not in the restricted area.
Note that for movements of host material out of the restricted area, permits may be required. Please see restricted area information below regarding permit requirements.
To view the full Government gazette order regarding the restricted area including the corrigendum dated April 9, 2015, please refer to the following links:
What does giant pine scale look like?
Giant pine scale produces a distinctive white, cotton-like wax secretion (Figures 1-3). The adult scale insect can be up to 12 millimetres in length.
The insect prefers the lower part of the tree and mainly occurs on the trunk, but it may also be found on branches well up in the canopy, and even on exposed roots.
In addition, look out for the black sooty mould which may grow on the large amounts of honeydew produced by the insects as they feed on plant sap.
Figure 2. Giant pine scale on the lower trunk of a pine tree (left) and on pine branches (right), both showing the typical white wax secreted by the insect
Figure 3. Giant pine scale adult, showing its white wax secretion (image courtesy of Andrea Battisti, Universita di Padova, Bugwood.org)
Figure 4. Giant pine scale eggs on Pinus radiata
How does it spread?
Giant pine scale moves slowly. Females do not have wings and the winged males are rarely seen. Infestations where trees are close together may be of higher risk, as the insect can more easily move from tree to tree.
However, giant pine scale can also spread with human assistance. If you are working with host trees, it is important to make sure you minimise the risk of spreading the pest.
What is the impact of giant pine scale?
Reports from Europe indicate that large populations of giant pine scale can cause severe dehydration and dieback of branches. In some cases, this is followed by tree death.
So far, pine death has been observed mainly in southern Greece and Crete.
The pest has also caused defoliation of Pinus species in parts of Italy and Turkey, with a significant impact in urban and forest environments.
What trees does it affect?
In Melbourne and Adelaide, giant pine scale has been found on the following pine species:
- Pinus halepensis (Aleppo pine)
- Pinus radiata (Monterey pine)
- Pinus pinea (stone pine)
However, overseas, giant pine scale has also been recorded on the following species:
|Pinus brutia||P. sylvestris|
|P. kochiana||P. laricio tauricus|
|P. nigra salzmannii||P. sosnowskyi|
|Abies cephalonica||A. nordmenniana|
|Picea engelmanni||P. orientalis|
Which trees are not affected?
Trees which may look similar to pines, spruces and firs, but are not hosts of giant pine scale, include cypresses and Araucaria, Allocasuarina, Casuarina and Callitrisspecies.
There are currently no technically feasible eradication options available for giant pine scale. If you have giant pine scale on your property, you may consider removing any infested trees on your property to reduce the spread. A permit is required for this work.
To avoid the spread of giant pine scale please do not touch, move or collect any samples or parts of infested trees including mulch, pine cones and needles.
How you can help
While the transition to management plan is being developed, restrictions on the handling and movement of giant pine scale host materials are in place to try to limit the spread of this pest.
Before leaving a host tree location, check your clothing, machinery and tools for signs of the pest.
Should you need to prune or destroy any host trees located on your property, please contact Agriculture Victoria on 136 186 or email firstname.lastname@example.org to arrange a permit prior to the commencement of any works.
If you suspect there is giant pine scale on any trees that have not already been tagged by Agriculture Victoria, please report the detection to Agriculture Victoria by:
- Phoning the Customer Service Centre on 136 186, or,
- Emailing photos of the suspected pest, together with a contact phone number and the pest's location to email@example.com.