How to tell if ground insects are becoming a pest to lawns in Wilmington

This question came to us this week - “How do you know if pearl bugs are present under a lawn?” The inquirer was actually referring to an insect pest of warm-season turfgrasses, the type we grow here in southeastern North Carolina, called ground pearls (Margarodes spp.). Our brilliant Consumer Horticulture Program Assistant, Miles Buddy, offered this advice: “Ground pearls are a type of scale insect that live underground and attach themselves to roots, feeding on plant juices. The pattern of dieback in turf is often roughly circular and often most obvious during periods of drought. Small, irregular patches will yellow and die by fall. The infested patches grow slowly with each growing season as the insects spread outward. Centipedegrass is most severely affected, but zoysia, St. Augustine, and bermudagrass are also susceptible.

To diagnose ground pearls, look among the roots, about 2-3 inches below the surface. Sample along the borders of stressed patches – pests and pathogens aren’t active in dead turf (“dead men tell no tales”). Ground pearls nymphs will appear as abundant spherical particles less than 1/6 inch in diameter. These nymphs are lustrous and whitish-yellowish. Adult females are pink.

There are no chemical management options for this pest. Some pyrethroid formulations are labeled for ground pearl, but research shows they are ineffective. Broad spectrum insecticide application may increase ground pearl presence by eliminating their predators. The current best management approach is to maintain a vigorously growing turf through proper fertilization, irrigation, and mowing.” For more information on ground pearls, visit: https://www.turffiles.ncsu.edu/insects/ground-pearls-in-turf/

If you have turf problems and want some help, Cooperative Extension can facilitate turf pathology testing through the Turfgrass Diagnostics Lab at NCSU. For more, go to https://turfpathology.ces.ncsu.edu/diagnostic-lab/how-to-submit-a-sample/. If you want to submit a sample, please follow their sampling instructions and bring the material to our offices during Plant Clinic Hours. Our plant clinic is staffed by Extension Master Gardener volunteers and is open on weekdays from 10 a.m. – 4 p.m., located at 6206 Oleander Dr. in Wilmington.

A take-away here is the best turf pest prevention is to “maintain a vigorously growing turf through proper fertilization, irrigation, and mowing.” Here is a good resource: https://content.ces.ncsu.edu/carolina-lawns

Lloyd Singleton is the director of the N.C. Cooperative Extension – New Hanover County Center and Arboretum, located at 6206 Oleander Drive, Wilmington. He can be reached at lsingleton@nhcgov.com or 910-798-7660. The grounds of the arboretum are free and open daily from 8 a.m. to 5 p.m.