The mature adults are an orange-brown colour with a softer white, fluted covering which is actually an egg sac. The scale itself is only 5 mm, but the egg sac can be as much as three times as big.
The adults of this species don’t lose their legs, but they tend to find a spot to feed and stay there.
The young, called crawlers, can move about in search of a place to feed. They tend to only move after each moult, leaving their old waxy covering behind. Once they reach maturity they will build their egg sacs and start to lay eggs.
Males are extremely rare and in many colonies not present at all.
Adult size: 10-15 mm
Out and about
They are most abundant in late summer. This scale is an Australian native, but is now a pest in most tropical, subtropical and temperate regions including southern Europe and U.K, Africa, Nth America, Oceania, Sth America, New Zealand and Asia. In Australia they are found mainly in the south-eastern regions but are present further north.
Reproduction and Life cycle
Like other scale, the female does not need a male to produce offspring. The egg sac can contain up to 1000 eggs, usually hatching in autumn. The time from egg to adult is about 2 months, with two generations a year.
To deter
To control
Sprays are particularly effective on the young crawlers before they have developed their waxy coatings
Spray with:
- Soapy water
- White oil
- Neem oil
- Tea of garlic, nettles, basil or wormwood or a combination
- Pyrethrum if infestation is bad, but this will also harm beneficial insects
If ants are protecting them, sprinkle diatomaceous earth around the base of the plant. See the information on ants for other methods of dealing with them.
Plants to repel
Plants to attract
Predators
Lacewings / Lady beetles / Minute pirate bug
Parasitoid wasps
Why they are a Pest
They suck the sap of plants, which can affect its growth, weakening it and distorting the new growth. Heavy infestations can severely affect the health of the plant.
As with aphids these scale secrete honey dew that attracts ants, which in turn, protect and ‘farm’ the scale. The honey dew will cause sooty mould.
They attack a wide range of plants and are very common on citrus trees.
The honey dew itself can grow a fungus called sooty mould, which will not kill the plant but it will inhibit photosynthesis.
