Giant pine scale

Giant pine scale (GPS) (Marchalina hellenica) is a large insect that lives by sucking the sap of pine, fir and spruce trees.

If left unmanaged, this insect can build up to large numbers. Heavily infested trees can dry up and die, impacting our parks, forests, softwood plantations and residential properties.

An active containment program is under way in Victoria. Early reporting is essential to stop the spread. You can report suspected sightings of giant pine scale to Agriculture Victoria by using the public online reporting form or phoning our customer contact centre on 136 186.


GPS is a large, sap-sucking scale insect that reaches a length of 8 to 19 mm long and 3 to 5 mm wide (Figure 1).

It produces a distinctive, white cotton wool-like waxy secretion that is a by-product from sap feeding. The waxy substance protects the insect and eggs from drying out (Figure 2) and is visible in the cracks of the rough bark on the trunks (Figure 3) and branches (Figure 4) of pine trees.

The pest typically prefers the lower part of the tree but will move on to branches as numbers increase.

Photo of an adult giant pine scale taken under a microscope showing the dorsal (top) view and underside of the insect.

Photo of a cluster of yellow giant pine scale eggs, sourrounded by white wax on Pinus radiata.

Photo of a large pine tree trunk with white wax spots from giant pine scale.

Photos of pine tree branches covered in white wax spots secreted by giant pine scale

Potential impact of feeding damage

Giant pine scale live in large numbers and can affect the health and safety of the trees they live on.

Heavily infested trees can dry up from the insects feeding on the tree's sap, which cause wilting, early needle drop and branch dieback. This results in tree decline, which is made worse by high-density settlement of the host tree by bark beetles that can detect plant stress and preferentially attack weakened trees.

The honeydew secretions can also make the tree susceptible to infections by sooty mould.

The potential effect of GPS on commercial softwood plantations would be economically damaging to the industry.

Host trees

In Australia, GPS has been detected on 3 host species of pine:

  • Pinus halepensis (Aleppo pine)
  • Pinus radiata (Monterey pine)
  • Pinus pinea (stone pine)

Overseas, giant pine scale has also been found on:

  • pines (Pinus brutia, P. sylvestris, P. kochiana, P. laricio tauricus, P. nigra salzmannii, P. sosnowskyi)
  • firs (Abies cephalonica, A. nordmenniana)
  • spruces (Picea engelmanni, P. orientalis).

Non-host trees

Trees that can look similar to pines, spruces and firs but are not hosts of giant pine scale include cypresses (Araucaria, the monkey puzzle tree), she-oaks (Allocasuarina, Casuarina) and cypress-pines (Callitris).


GPS has one generation per year.

Between November and January each year, adult females produce 300 to 400 eggs that are retained within the female body and hatch after the death of the female.

There are 2 juvenile stages (called crawlers). The first stage crawlers are initially only 1 mm in length and are present between late November and May. The second stage grows up to 7 mm in length and appears between May and September.

Adult females do not have wings. The winged males are rarely seen.


This insect is native to eastern Mediterranean regions – specifically, Greece and Turkey.

Giant pine scale in Victoria

Giant pine scale was confirmed in Melbourne's south-eastern suburbs and in Adelaide for the first time in 2014.

Infested trees are present in suburban Melbourne and current known areas of GPS infestation can be found on the map below (Figure 5).

Map with orange shading showing suburbs of Victoria impacted by Giant Pine Scale at the time of publishing including Coburg North, Rosanna, Kilsyth, Montrose, Mount Waverley, Clayton, Oakleigh South, Macclesfield, Avonsleigh, Emerald, Belgrave South, Lysterfield, Narre Warren East, Dandenong North, Endeavour Hills, Narre Warren North, Harkaway, Beaconsfield Upper, Berwick, Tynong North, Tyabb and Hastings.


Giant pine scale spreads by moving up and down and between host trees, up to 50 m in one year.

People can also unintentionally spread it when they:

  • move infested plant material (for example, branches, mulch and logs)
  • use contaminated gardening equipment
  • carry it on clothing, machinery and cars.

So it’s important to take precautions to avoid spreading the pest to other trees.

Managing giant pine scale

There’s a new insect being found in Melbourne’s south-east called giant pine scale. Giant pine scale is a tiny scale insect that feeds on the sap of pine, fir, and spruce trees. Between November and January, each female produces over 300 eggs, which hatch into crawlers between late November to May. Giant pine scale infested trees have white cotton wool-like wax on their trunks and branches. Adults typically prefer the trunk; however, it can also be found on branches. They continue to grow up to 12 millimetres, and around September, they produce eggs within their bodies and eventually die.

The problem with giant pine scale is that they eventually kill trees they live on. Heavily infested trees can dry up and die from the insects drinking the tree’s sap, impacting parks, forests, plantations and homes, and the aesthetic value of neighbourhoods if not managed.

Giant pine scale spreads by crawling between host trees and by people moving infested plant material, gardening equipment, and machinery. Take care to avoid spreading the pest if it’s on your property or one you’re working on. Consider cutting down the entire tree. Dispose of infested tree material via your green rubbish bin or by leaving them on your property if there is enough land. Clean all plant material off used gardening equipment using a solution of 80% methylated spirits and 20% water, and paper towel.

For advice on managing trees on your property, speak to an arborist or tree specialist. Arborists or tree specialists who work with host or infested trees should practice good hygiene to avoid spreading giant pine scale to other properties. Check and decontaminate your clothing, machinery and tools for signs of pest, soil or plant material before leaving the property.

When transporting infested material for disposal, remember to fully cover up your load, so that infested plant materials don’t fall off during transit. If you find giant pine scale on a pine, spruce or fir tree outside of Melbourne’s south-east, report it to Agriculture Victoria. Avoid collecting samples from infested trees, as this can spread the insect further.

For more information on managing giant pine scale, visit

The following gardening and equipment hygiene tips will assist residents, landholders, gardeners and contractors in managing giant pine scale-infested trees to avoid further spread.

Residents and landholders

If you have giant pine scale on your property, there are a range of things you can do to help minimise its spread:

  • Where possible, keep fallen or cut tree branches on your property.
  • Cut any infested branches that hang over the house or any structures (for example, sheds, tanks, swings and fences).
  • Dispose of unwanted tree branches, needles and pine cones using your green waste or local council transfer station (remember to bag or cover your waste during transport).
  • Clean all plant material off gardening equipment using an 80% methylated spirits to 20% water solution and a brush or paper towel.
  • If you decide to have the tree removed, hire an arborist who has been trained in handling giant pine scale -nfested trees.

Contractors working with infested trees

When working on infested trees, it's important to practise good plant and equipment hygiene to avoid spreading giant pine scale to other properties:

  • When entering a site, take a hygiene kit with you that includes paper towels, 80% methylated spirits to 20% water solution, a bristle brush, disinfectant wipes, plastic bags and spare clothes.
  • Check the site for any pests or diseases.
  • Clean and decontaminate equipment between trees using the methylated spirit solution or disinfectant wipes.
  • Clean and decontaminate your machinery, tools and clothing (or change into spare clothing) before leaving the site.
  • When transporting infested material for disposal, remember to fully cover your load so insects don't escape during transit and to dispose of material to avoid further spread.

Other resources

Take the Giant pine scale eLearning course. Note this course is hosted on the Agriculture Victoria learning management system. Please register and choose this course from the goals catalogue.

Photo credits

Figures 1–5, Agriculture Victoria, Department of Energy, Environment and Climate Action (DEECA).

Reporting an unusual plant pest or disease

Report any unusual plant pest or disease immediately using our online reporting system or by calling the Exotic Plant Pest Hotline on 1800 084 881. Early reporting increases the chance of effective control and eradication.

Please take multiple good quality photos of the pests or damage to include in your report where possible, as this is essential for rapid pest and disease diagnosis and response.

Your report will be responded to by an experienced staff member who may seek more information about the detection and explain next steps.

Report online

Page last updated: 14 May 2024