Ground Pearls
Margarodes spp.


DAMAGE DESCRIPTION:

Infested turfs turn yellow, then brown in summer, and die in fall in irregular patches; examination of sod plug at 2 to 3 inch soil depth reveals globular, whitish, pearl-like shells attached to the roots; immature nymphs occur on roots as small, yellowish-purple, pearl-like cysts; pinkish scale insect covered with hard, globular shell up to 2 mm in diameter; root sucking insect; typically occurs in warm humid climates; these are immature stages of a scale insect; can occur as deep as a foot in the soil; injure plants by removing liquids containing carbohydrates and minerals from the roots.

HOST GRASSES:

Mainly attack warm season turfgrasses-Centipedegrass, Bermudagrass, Zoysiagrass, St. Augustinegrass

LIFE CYCLE:

Nymphs hatch from eggs during the summer, crawl onto the grass roots, and attach needle-like sucking mouthparts; protective, cyst covering forms rapidly, under which immobile nymph matures; 1 year life cycle.

FACTORS THAT MAY PROMOTE INSECT DAMAGE:

Monitor turf for injury symptoms and check under sod for the pearl like shells.

CULTURAL CONTROL:

Proper fertility, watering and mowing to keep grass healthy; fumigate to depth of 12 inches and reestablish; follow sanitary practices to prevent introduction, as is frequently introduced on vegetative sprigs, plugs, and sod.

CHEMICAL CONTROL:

Little if any effectiveness from insecticides, mainly because of the depth they can reach.

Specific Insecticide Recommendations
Insecticide
(chemical name)
Efficacy Application
Interval
Time of Year
To Apply
Example of Products
(trade names
Permethrin Poor to Fair As needed Summer Prelude, Astro
Malathion Poor to Fair As needed Summer Malathion
Trichlorfon Poor to Fair As needed Summer Dylox, Pronto

REFERENCES:

Beard, J. B. 2002. Turfgrass Management for Golf Courses. Second Edition. Ann Harbor Press. Chelsea, Michigan..

Decker, H. F., Decker, J. M. 1988. Lawn Care-A Handbook for Professionals. Prentice Hall. Englewood Cliffs, New Jersey.

Liskey, E., “Turfgrass Insecticides”, Grounds Maintenance, Volume 37, Number 2, February 2002, pp. 8-10.

Turgeon, A. J. 2002. Turfgrass Management. Sixth Edition. Prentice Hall. Upper Saddle River, New Jersey.

Taylor, G. R. - Editor. 2000. Turfgrass Pesticide Recommendations 1999-2000. Extension Publication SCS-1991-01. Texas A&M University. College Station, Texas.

Emmons, R. D. 2000. Turfgrass Science and Management. Third Edition. Delmar Thomson Learning. Albany, New York.