Giant pine scale

Adults

• Up to 8–13mm long and 4–6mm wide.
• Roughly ellipsoid shaped with tiny legs.
• Yellowish, covered by a fluffy, waxy, white secretion for protection.
• Females do not have wings, and the winged males have rarely been seen.

Eggs

• Oval shaped and yellow in colour.
• Laid in fissures in the bark, beneath a white, waxy, cottonish layer.

Nymphs

• Ellipsoid shaped and pale yellow in colour. They develop a covering of waxy, fluffy white secretion.
• Initially they are tiny, about 1mm long, and grow to about 7mm long.
• The nymphs are commonly called 'crawlers' because they have legs and are able to move within or between trees.

Plant stage and plant parts affected

Trees of all ages are susceptible. Giant pine scale prefers the lower parts of the tree and occurs mainly on the trunk. It may also be found in the canopy and on exposed roots.

Plant damage

Severely infested trees can become dehydrated, resulting in wilt, needle drop and branch dieback that can eventually kill the trees. Affected trees also become weakened and susceptible to attack by other organisms such as insects.

Giant pine scale has been attributed to reducing the growth of trees.

Giant pine scale is fairly distinctive in that it produces an obvious covering of white, waxy, cotton-like secretions that are visible on infested trees. If you think you have seen giant pine scale:

• report online
• call Biosecurity Queensland on 13 25 23
• call Exotic Plant Pest Hotline on 1800 084 881.

In Australia, giant pine scale has been found in Victoria and South Australia. The pest has not been found in Queensland.

Giant pine scale is native to the eastern Mediterranean area, particularly the Italy, Greece and Turkey region.

Giant pine scale affects plants from the family Pinaceae.

Australia

Hosts include:

• Pinus halapensis (Aleppo pine)
• Pinus pinea (stone pine)
• Pinus radiata (Monterey or radiata pine).

Pinus radiata is a new host record for the pest and as the pest is new to Australia, the host range may increase further.

Worldwide

Giant pine scale has been detected on:

• pines
  • Pinus brutia (Turkish pine)
  • Pinus nigra subsp. laricio (Corsican pine)
  • Pinus nigra (black pine)
  • Pinus sylvestris var. hamata (Caucasian pine) (P. kochiana and P. sosnowskyi)
  • Pinus sylvestris (Scots pine)
• firs
  • Abies cephalonica (Greek fir)
  • Abies nordmanniana (Caucasian fir)
• spruces
  • Picea engelmanni (Englemann spruce)
  • Picea orientalis (Oriental spruce).

Similar species

Trees which may look like pines, spruces and firs, but are not known to be hosts of giant pine scale include cypresses and Araucaria, Allocasuarina, Casuarina and Callitris species.

• The nymph grows through 3 developmental stages (instars) before becoming an adult, with males having an extra instar stage.
• First instar stage nymphs emerge in late spring/early summer.
• When females feed, they secrete a cotton-like waxy flocculent and honeydew.
• Honeydew production ceases when giant pine scale becomes an adult.
• Giant pine scale females can reproduce without males and males are rarely seen.
• Each female can produce over 300 eggs between November and January, which then hatch into crawlers.

Pine tree death has primarily been observed in southern Greece and Crete, where large scale infestations have occurred. In Italy and Turkey, the pest has caused defoliation in urban and forest environments, but no tree deaths have been reported.

The impact of giant pine scale on commercial softwood forestry plantations in Australia is unknown, however it is known that severely infested host trees can experience reduced wood strength and density. It is expected that hosts will experience defoliation, smaller growth increments and reduced wood quality.

Weakened infested trees (and trees suffering dieback or tree death) in backyards, parks and gardens can result in loss of shade, wildlife habitat and social amenity.

Long distance spread is most likely to occur when people move infested plant material, and soil and gardening equipment or machinery that has been in contact with infested plants.

Localised spread can occur within plantations or other host trees closely planted together as the immature mobile stage (crawlers) of the scale insect can move within and between trees.

The Biosecurity manual for the plantation timber industry (PDF, 1.9MB) provides advice on how to monitor your plantation for early detection of pests and diseases.

To avoid spreading it, do not touch, move or collect suspect samples or parts of infested trees.

If you think you have seen giant pine scale:

• report online
• call Biosecurity Queensland on 13 25 23
• call Exotic Plant Pest Hotline on 1800 084 881.

• Use pest-free plant propagation material.
• Practise good plantation/farm biosecurity—ensure your equipment and machinery is clean before taking it to other properties, and inspect equipment or machinery on arrival to your property to ensure they are clean and free of plant material or soil.

Protect your farm from plant pests and diseases:

• Protect your farm from emergency plant pests
• Understand good farm biosecurity
• Visit the farm biosecurity website

Giant pine scale is prohibited matter under the Biosecurity Act 2014.

Report suspected giant pine scale immediately by calling Biosecurity Queensland on 13 25 23 or the Exotic Plant Pest Hotline on 1800 084 881.

If you think you have found giant pine scale, you must take all reasonable and practical steps under your control to minimise any associated risks. This is called a general biosecurity obligation (GBO).