Ground pearls are scale insects that live in the soil and suck the fluids from the roots of most turfgrasses, but prefer centipedegrass and bermuda grasses. Ground Pearls are shaped like pearls, hence the name. They occur throughout Florida, but are more abundant in northern and north-central Florida. Lawns that are well maintained, are less likely to be attacked by ground pearls. They prefer the sandier soils and drier conditions.
Clusters of pinkish-white eggs, covered in a white waxy sac, are laid in the soil from March to June. Tiny crawlers hatch from eggs, find a root, insert their piecing-sucking mouthparts, and cover themselves with a hard, yellowish to purple, globular shell. These round “pearls” range in size from a grain of sand to about 1/16" in diameter. They may occur as deep as 10" in the soil. After emerging from the “pearl”, the adult female is 1/16" long, pink-colored, with well developed forelegs and claws. Adult males are rare, tiny, gnat-like insects. One generation may last from 1 to 2 years, or longer.
Symptoms attributed to ground pearl injury are first a yellowing and then browning of the grass. Stressed grass is most susceptible to injury, and may not be able to outgrow or survive ground pearl feeding damage. Properly watered and well-managed lawns often lack symptoms despite being heavily infested. Other factors such as disease, nutritional inbalances, drought or nematodes (especially in centipedegrass) may cause off-color areas in lawns. The lawn should be carefully examined to determine which corrective measures may be needed. Weeds also tend to invade areas infested with ground pearls.
Minimize plant stress and maintain proper fertility and soil moisture to help grass tolerate the damage. No insecticides are currently available for ground pearl control.