Giant pine scale
Giant pine scale (Marchalina hellenica) is a tiny scale insect that lives by sucking the sap of pine, fir and spruce trees. Adults grow up to 12 millimetres in length. Each female produces over 300 eggs between November and January, which then hatch into crawlers.
Giant pine scale infested trees have white cotton wool-like wax on their trunks and branches. While the insect typically prefers the lower part of the tree (i.e. trunk), it can also be found on branches and exposed roots.
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 radiate
Giant pine scale was confirmed in Melbourne's south-eastern suburbs for the first time in 2014. Over 4,300 infested trees exist across 162 properties in Tynong North, Macclesfield, Narre Warren East, Narre Warren North, Beaconsfield Upper, Harkaway, Berwick, Dandenong North, Mount Waverley, Clayton, Oakleigh South and Tyabb.
Information resources on giant pine scale
Managing giant pine scale in Victoria eLearning course (note this course is hosted on the Plant Health Australia website, please register and choose this course from the ‘Browse learning’ tab).
Why is giant pine scale a concern?
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 and die from the insects feeding on the tree's sap, impacting our parks, forests, softwood plantations and residential properties if not properly managed.
How does it spread?
Giant pine scale spreads by crawling to nearby host trees.
People can also unintentionally spread it when moving infested plant material (e.g. branches, mulch and logs), using contaminated gardening equipment and carrying it on clothing, machinery and cars, so it's important to take precautions to avoid spreading the pest to other trees.
- Pinus halepensis (Aleppo pine)
- Pinus radiata (Monterey pine)
- Pinus pinea (stone pine)
Overseas, giant pine scale has also been found on the following species:
- Pines (Pinus brutia; P. sylvestris; P. kochiana; P. laricio tauricus; P. nigra salzmannii; P. sosnowskyi)
- Firs (Abies cephalonica; nordmenniana)
- Spruces (Picea engelmanni; P. orientalis)
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.
How to manage giant pine scale
There are currently no effective chemical treatment options available for giant pine scale. In addition to the resources available under Information resources on giant pine scale, 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, any structures (e.g. shed, tanks, swings and fences).
- Dispose of unwanted tree branches, needles and pinecones using your green waste or local council transfer station (remember to bag/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 infested trees.
Contractors working with infested trees
When working on infested trees, it's important to practice good plant and equipment hygiene to avoid spreading giant pine scale to other properties.
- Take a hygiene kit with you when entering a site containing 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 that may be present.
- 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.
Report detections outside of Melbourne's south-east
If you find giant pine scale on a pine, spruce or fir tree outside of Melbourne's south-east (i.e. in the green parts of the map below), report it to Agriculture Victoria.
- Phone the Customer Service Centre on 136 186.
- Email photos of the suspected pest, together with a contact phone number and the pest's location to plant protection.
Use the interactive map below to find out if you have found giant pine scale in a new location.
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 is displayed within a green area, you are in a non-infested area.