As many of you know, ground pearl is a common enemy of turf in our area. Recently, I came upon a great article that I would like to share with all of you from the North Carolina Cooperative Extension. Please see the following excerpt from “What is Killing My Lawn”:
IDENTIFYING GROUND PEARL
Lawns infested with ground pearl exhibit dead areas where little grows except a few weeds. These areas may be only a few inches across or up to several feet in size depending on how widespread the ground pearl are, and are often roughly circular in shape. The dead areas expand slowly, by up to a foot each year. If grass is replanted in these spots it usually dies within a year.
Ground pearl infestations can be confirmed by digging in the soil where the insects live. As their name implies, ground pearl are small, round insects that are pearly white to tan in color. They look similar to the pellets of slow release fertilizer found in container grown plants. If you suspect ground pearl in your lawn, dig into the soil 3” to 4” deep around the edges of dead areas and carefully sift through the soil in your hand to find the pearl like insects. Since ground pearl occur in clusters, be sure to check several locations before ruling ground pearl out.
MANAGING INFESTED LAWNS
There are no pesticides that kill ground pearl, which are a type of scale insect. Since only turf grasses are effected by ground pearl one method of dealing with them is to redesign your yard so that trees, shrubs, and flowers are planted in the infested areas. On their own, ground pearl only move a few inches each year. Be very careful not to spread them around when moving soil or using tools or equipment in infested areas. The movement of soil and contaminated equipment is the main way ground pearl are spread over large areas.
While all of the turf grasses grown in our area are susceptible to ground pearl, centipede is the most sensitive. Centipede lawns infested with ground pearl should be redesigned or converted to a more tolerant lawn grass. In a recent trial conducted by NC State University, ‘El Toro’ zoysia tolerated ground pearl damage better than other species in the study. Though often considered a weed, bahiagrass has also been found to be relatively resistant to ground pearl damage. Very vigorous turf grasses like ‘Celebration’ bermuda can be grown in ground pearl infested areas if they receive supplemental irrigation and fertilization. This is more effective in heavy or clay soils. In deep sandy soils it is much more difficult to maintain a dense lawn if ground pearl are present, even when vigorous turf species are planted.
Ground pearl can be found as deep as 10” or more in the soil and can live for 15 years or longer even when no grass is present. Excavating large areas of soil in the hope of removing ground pearl is a very expensive and minimally effective control strategy. Any insects left behind will repopulate new soil relatively quickly since each female is able to produce one hundred or more offspring each year without mating. Excavating soil also increases the risk of spreading these pests to new areas….”