PEST
 
   NAME
     White Wax Scale
     Ceroplastes destructor
 
   ORDER
     Hemiptera
 
   FAMILY
     Geometridae

Description of the Pest
The mature female scale is a large, conspicuous white waxy scale and is up to 10mm (6/16in) long and has an irregular shape resembling a blob of wax. The scales have one generation per season and only live for one year. The eggs are laid under the female scale before it dies. The male scale is not found in Australia.

Appearance of the Pest
These insects have a Hemimetabolous life cycle, ie. When the immature nymphs resemble the adults.
The Crawlers appearing from beneath the female scales in a single group during late spring
The nymphs are normally found on the mid ribs and veins of the leaves and the adults on the small twigs. The female scales can lay up to 1,000 sand-like eggs that are bright pink.

Period of Activity
The new scales are seen during early summer preferring high humidity, but high temperatures will reduce numbers.

Susceptible Plants
Wide ranges of native, ornamental and evergreen fruit trees are susceptible, including Citrus, Mango, Gardenias, Syzygium species, Dodonaea species, Boronia species, Eriostemon species and some fern species.  

Lagerstroemia indica is attacked by the Florida Wax Scale (Ceroplastes floridensis) in the northern hemisphere. 

Damage Caused
There is often on obvious damage from the nymphs and adults piercing and sucking the sap from the plant. Heavy infestations may cause dieback of the twigs and the honeydew may encourage sooty mould, which reduces the plants capability of photosynthesis.

		  Sooty Mould

Cultural Control
Dead or damaged parts of the plant should be removed and destroyed including fallen fruit. Small infestations may be removed by hand or squashed on the stems. Healthy plants are less susceptible to attack, so maintain vigour of the plant and avoid using high-nitrogen fertiliser that produces excessive soft young growth.
When pruning susceptible plants paint the cuts with antifungal sealant paint as scale insects are attracted to the sweet smell of the sap. This will reduce the infection rate of the plant. 

Biological Control 
Natural predators such as parasitic wasps may reduce numbers of active nymphs; parasitic wasps are bred commercially in some areas for this purpose. It should be noted, however, that wasps would avoid dusty conditions. 
Other predators that assist in control are assassin bugs, ladybirds, lacewings, hover flies and scale eating caterpillars. A variety of birds also attack scales. 
The control of ants that transport aphid from one host to another also reduces infestation and can be carried out by applying at least three greased bandages 5mm apart around the stem or trunk of the plant. 

   Assassin Bug Nymph    Hover flies

Chemical Control
Spray the entire plant with dilute white oil solution; a follow-up spray may be required after four weeks, for heavy infestations. Spraying of chemicals will also kill of natural predators and in some cases the secondary scale infestation is more prolific especially when using copper based chemicals.
Some chemical controls, such as methidathion, are available - please seek advice from your local nursery as to the suitable product for your area.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.