As an Extension Agent, I often get asked about ground pearls. Because we have sandy soil here in Carteret County, it’s easy to blame something that can’t be easily seen for problems with the turf. Here are several questions with answers that I often get asked about ground pearls.
Ground Pearls in Turf
What are ground pearls? They are an insect that feeds on the roots of turfgrass. They hatch out of an egg in early spring and crawl in the soil until they find a root of some turfgrass where they insert their piercing-sucking mouthpart into the root and then create a creamy or gray shell around themselves, very much like a shell of a scale insect. They are more prevalent in sandy soils than they are in heavy clay soils.
What do ground pearls look like? In the spring when the crawlers hatch out and are moving around in the soil, they are pink and fleshy. This is actually the best time to see them. They stand out from the soil, making them easy to find. Here in Carteret County that is usually in late May or early June. After they have formed the shell around themselves they are either creamy or gray in color and round to egg shaped, and they are about the size of a large piece of sand or maybe a little larger, but the shells are smooth rather than angular like sand.
What can be done to control ground pearls if they are found in the lawn? Currently the best recommendation is to maintain a healthy lawn by following the lawn maintenance calendar for the lawn grass that you have. Use the correct mowing height and frequency so that no more than one third of the grass height is being removed at any one time. Keep the lawnmower blade sharp. Irrigate when needed to keep the grass growing. Also fertilize the lawn so it has the nutrients needed in order to grow. There are currently no known chemicals that offer effective control of ground pearls on the market. A healthy and vigorous lawn is the best defense against ground pearls.
How do I know if I have a problem with ground pearls? The damage ground pearls cause looks very similar to some other turf problems, so finding the actual insect is the best way to know that ground pearls are present. Ground pearls usually cause a roughly circular pattern of death in the lawn. These dead areas usually get larger in the summer when the grass should be growing vigorously. Another symptom is that there is usually no grass growing in the center of the dead area, only weeds may be found there. In the summer and fall dig a small hole in the dying grass on the edge of the hole and look for the pearls in the soil. In the spring (May and early June) dig in the green grass at the edge of the dead area and look for the pink crawlers.
If you still have questions about ground pearls in the lawn, take a look at TurfFiles that offers some good information. There are several links to other publications on that site that can be explored as well.
A healthy and vigorous turf is not only beautiful, but it’s also the best defense against many problems in turf.