Giant pine scale
- Current situation
- How to report infestations and contact us
- What does giant pine scale look like?
- How does it spread?
- What is the impact?
- What trees does it affect?
- Which trees are not affected?
- Control methods
- How you can help.
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.
In Victoria, giant pine scale has been found on over 4,300 infested trees across 162 properties in the south east suburbs of Melbourne.
The suburbs where giant pine scale is found include: Tynong North, Macclesfield, Narre Warren East, Narre Warren North, Beaconsfield Upper, Harkaway, Berwick, Dandenong North, Mount Waverley, Clayton, Oakleigh South and Tyabb.
Agriculture Victoria began surveillance and treatment of infested trees in in October 2014 to protect Australia's $1.16 billion softwood plantation industry from the threat of giant pine scale. A Restricted Area for giant pine scale was declared under the Plant Biosecurity Act 2010 to contain giant pine scale within known infested sites
Agriculture Victoria has inspected over 75,000 trees which were chemically treated. This measure did not work effectively and live scale insects remain on infested trees. Agriculture Victoria will continue to work with industry and stakeholders to minimise the impact of the pest on urban communities and softwood plantation industries.
As of 7 April 2017 the Restricted Area no longer applies. This means a permit is no longer required to work on host trees within the former Restricted Area or move host material. All affected stakeholders and permit holders have been notified of this change.
It is still important to exercise good hygiene practices when working on host trees (pine, spruce and fir) to prevent any further spread of giant pine scale and to protect Australia's valuable softwood industry.
How to report infestations and contact us
If you suspect there is giant pine scale on any tree that is located in the green area, or that 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
- Emailing photos of the suspected pest, together with a contact phone number and the pest's location to firstname.lastname@example.org.
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 area, you are in the infested area.
If your address lies within a green area, you are not in the non-infested area.
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 1. Giant pine scale on the lower trunk of a pine tree
Figure 2. Pine branches 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 by employing sustained hygiene best practices.
What is the impact?
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)
In other countries 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 Callitris species.
There are currently no effective 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 no longer required for this work.
How you can help
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, following hygiene standards or using an arborist experienced in the removal of trees infested with giant pine scale is recommended.