In WA, pink ground pearls seem a greater problem as grasses seem to tolerate high numbers of white ground pearls without noticeable damage.
Immature stages and adult females of both species feed on the root systems of grasses which may cause slight to severe wilting depending on their populations and the general health of the lawn. Ground pearl spread and resultant damage may increase more rapidly with cultivation or mechanical soil aerating.
Description and distribution
Adult female ground pearls are 3-5mm long, 2-4mm wide and look like bright pink or pearly-white mealy bugs without a powdery coat. The immature stages of pink ground pearls form yellowish-brown, leathery capsules in which they live, well protected and encapsulated.
The cysts of white ground pearls are yellowish-white and shiny. The size of the cysts depends on the developmental stage of the insect.
Ground pearls are widespread in Queensland and northern New South Wales. In WA they have been recorded in lawns in the Perth metropolitan and some areas of the south-west.
In the United States Eumargarodes laingi Jakubski is found in North Carolina, and is widespread in Florida, Georgia and Alabama.
There are no management strategies known to combat this pest. No chemical is registered for its control and no effective biological agent (parasite or disease) is known.
The best defence is to minimise plant stress and maintain ideal nutrient uptake and watering. Well managed lawns can sometimes support heavy infestations of ground pearls and show no sign of damage.