Adult armyworm moths fly at night, depositing eggs in turfgrass. After hatching, the larvae grow up to two-inches long, developing light stripes along the green-gray body. The fall armyworm has a white inverted "Y" marking on the front of the head. They feed at night, hiding in the thatch during the day. Larval populations feed in mass, chewing grass blades and stems as they migrate to new turf area. Damage diagnosis is similar to sod webworms and cutworms.
Bluegrass billbugs and hunting billbugs on zoysia are two major weevil species responsible for severe turfgrass damage.
Adults become active in the late winter/early spring season, laying eggs in the stems and sheaths of grass plants. Upon hatching, the small, legless larvae begin feeding inside the stems, tunneling throught the brown and into the root zone, making control difficult. Damage appears as small, brown spots, which may coalesce to form large, brown areas. Dead grass is easily pulled away from the brown, revealing hollow stems with sawdust "frass" present in the chewed areas.
Black Turfgrass Ataenius Beetle
The small black turfgrass ataenius beetle favors golf course annual bluegrass turf. The adults become active in early spring, flying and depositing eggs in the soil. Eggs hatch from late spring to mid-summer. The larvae are very small and populations of 200 to 300 per square foot are not uncommon. Extensive root feeding may kill large turf areas. In most areas, a second generation of larvae is produced from first-generation adults, which feed on roots in late summer, making this insect a double threat.
Chinchbugs feed on turfgrass by sucking out plant juices and injecting salivary fluids into the leaves and stems, causing the plant to turn yellow before it becomes brown. Hot, dry, sunny conditions favor chinchbug activity. They feed on most cool and warm season grasses including St. Augustine and bermuda grass. Adult chinchbugs are about one-quarter inch long white wings folded over its black body. They remain actively feeding as long as warm conditions prevail, producing two or three generations per year.
Cutworms are the larvae of large, hairy, nocturnally-flying moths. The two most common species are the black and bronzed cutworm. Eggs are deposited by the adult moths throughout the summer months. After hatching, cutworms start feeding immediately, usually at night. They chew grass stems near the crown, leaving green excrement pellets. Starlings and blackbirds are also attracted to cutworms (as well as to armyworms and sod webworms).
Greenbug aphids have become a problem in cool-season turfgrass areas. Similar to the chinchbug, greenbugs, pierce leaf tissue, suck out the sap and inject salivary fluids, causing surrounding tissue to die. They are one-sixteenth-of-an-inch long with a fleshy green body. Greenbugs can feed anywhere, but are especially fond of turf under trees. The grass turns an orange color before dying. Greenbugs can feed from late spring to mid-fall.
Several mites species feed on various warm and cool season turfgrass. They are small and require a hard lens for identification. Mites feed on grass by sucking fluids out of the plants causing the grass to thin. The bermuda-grass mite is active during warm to hot growing conditions. The winter grain mite feeds on cool-season grasses from late fall through late spring with damage appearing similar to winter dessication. Turf damaged by clover mites seen in the spring has a silvery, dried out appearance, often apparent near buildings.
Mole crickets are a major pest in the southeast. The short-winged, tawny and southern mole crickets are most destructive. Adults are about one-half-inch long and lay their eggs in the spring, producing nymphs which feed near the surface, especially after rainfall or irrigation. Control during the young nymph feeding stages is most successful.
Small, beige adult webworm moths start flying over lawn areas during early summer usually at dusk, depositing eggs which hatch in seven to 14 days. The brown to gray caterpillars have dark, circular spots over their bodies. The larvae build tunnels in the thatch and feed on grass stems and leaves at night. Spotty, brown damaged areas where grass is easily pulled up above the soil and birds feeding are two signs of the sod webworms. Green pellets or "frass" in the thatch also may indicate webworm activity.
These are six natural predators of harmful insect species. These beneficial insects actually help control insects which damage turfgrass.
*Illustrations and descriptions provided by Lesco Turfgrass Insect Chart, 2003.