White Wax Scale

Latin name: Ceroplastes destructor

White wax scale is a sap-sucking insect commonly found throughout Western Australia on citrus, ornamentals and many native and exotic plants. Adult females are covered by a thick white waxy coating that protects them from predators and many insecticides. They feed by extracting sap from leaves, stems and twigs, weakening plants and producing sticky honeydew that promotes the growth of black sooty mould.

The crawler (juvenile) stage is the most susceptible to treatment, making correct timing essential for effective control.

Lifecycle

White wax scale undergoes incomplete metamorphosis.

Adult females lay hundreds of eggs beneath their waxy covering.
Eggs hatch into mobile crawlers that move onto leaves and young stems.
Crawlers settle and begin feeding, gradually producing their protective wax covering.
Mature females remain attached while feeding and reproducing.

In Western Australia, there is generally one generation each year.

Identification

Adults measure up to 8–10 mm across.
White to greyish-white waxy dome-shaped covering.
Immature crawlers are small, flat and pale yellow.
Found on twigs, stems and the undersides of leaves.
Heavy infestations produce sticky honeydew and black sooty mould.
Ant activity is commonly associated with infestations.

Damage

Yellowing and premature leaf drop.
Reduced plant vigour and shoot growth.
Sticky honeydew covering leaves and fruit.
Black sooty mould reducing photosynthesis.
Fruit contamination on citrus.
Heavy infestations may cause branch dieback.

SOLUTIONS

During the crawler (juvenile) stage on citrus and ornamentals: Apply Apparent Cocky to provide systemic control before the protective wax coating develops.

On established white wax scale infestations: Apply White Oil Spray thoroughly to smother exposed scale insects, ensuring complete coverage of branches and foliage.

Where crawler activity is high: Apply Malathion Garden Spray with White Oil Spray to improve control of juvenile scales before they mature.

For long-term protection of ornamental trees and shrubs: Apply Initiator Tablets to protect new growth against juvenile scale as part of an integrated management program.