Grubs

Grubs are the larvae of several kinds of beetles (green June beetle, May beetle, Japanese beetle, southern masked chafer, and white-fringed beetle). Many grubs remain in the soil for up to three years, burrowing and feeding on the roots of grass. Moles, skunks and birds feed on grubs and often damage turf searching for them. Heavy grub infestations can destroy grass roots, causing the area to become "springy" and allowing the mat of turf to be rolled back like a carpet. Certain species of grubs emerge from the soil and crawl on the surface of the ground. Larvae of the green June beetle may be identified by the unusual habit of crawling on their backs. Grubs may become numerous and cause severe damage to lawns and other turf areas.

Billbug grubs feed on the roots and burrow in stems of certain grasses. Adults feed on stems and leaves. Severe damage may occur if heavy populations of this pest are present. Several heavy infestations have been found in North Carolina recently.

Detection and Monitoring. Cut three sides of a 1-square-foot piece of sod about 3-inches deep with a spade at the edge of one of the off-color areas in the turf. Pull or pry the sod back like a flap and examine roots for chewed off remnants and check soil for grubs. Use fingers to sift through soil and roots. Treat if 3 or 4 grubs are found per square foot.

Mole Crickets, Burrowing Sod Webworms, Armyworms, and Other Caterpillars

Mole Crickets are light-brown crickets about 1½ inches long with short, stout forelegs and shovel-like feet. They feed on the roots of grass. Their burrowing also uproots seedlings and causes soil to dry out quickly. One mole cricket can damage several yards of a newly seeded area in a single night.

Burrowing Sod Webworms occasionally attack golf greens and lawns in North Carolina. The larva makes a hole about the size of a pencil a foot or more deep. Later the larva comes to the surface and forms a web while feeding. Heavy populations are very damaging to most grasses

Detection and Monitoring. Mark off a 1-square-yard area in a location of suspected infestations. Mix 2 fluid ounces of liquid dishwashing soap in 4 gallons of water and drench the square yard area with the solution. Insects will emerge to the grass surface. This requires getting on one's hands and knees to observe the area closely. Insects will return to the soil in 5 or 10 minutes. If no insects are found, examine other suspected areas.

1. Treat if an average of 40 or more sod webworms are found per square yard;

2. Treat if an average of 3 or more mole crickets are found per square yard.

3. Treat if an average of 8 or more caterpillars are found per square yard.

Ants, Bees and Wasps, Ground Pearls

Ants build nests in the ground. They are particularly troublesome around the fringes of golf greens, fairways and in lawns. The anthills and mounds often smother the surrounding grass. If ants nest about the roots of grass, they may destroy it. They also destroy grass seeds in the ground, which may prevent good stands of reseeding grasses.

Several species of bees and wasps occasionally damage lawns by digging up the soil, making holes or forming mounds. Some of these are the wild bees, cicada killer wasps and scoliids.

Ground pearls are small scale insects that resemble a miniature pearl. They attack the roots of grasses causing an unhealthy, unthrifty condition. Good management practices are essential since effective chemical controls are unavailable.

Detection and Monitoring of Other Insects

Closely examine turf for evidence of damage by ants, bees, wasps, and leafhoppers. The insect is most likely to be abundant at the border between the damaged area and the healthy grass.

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