Identifying Pests & Diseases
Surface Insects Commonly Found in Chicagoland
White Grubs
White Grubs are the C-shaped larvae of many different beetles, including Japanese, May, Oriental, Asiatic garden, June, European chafer and masked chafer. They feed on the fibrous root system of turf during the spring and fall months. Infestations over six to 10 grubs per square foot can be devastating to sod, causing large, brown areas of dead grass, which can be peeled back like a carpet. Fully-grown larvae are one-half to three-quarters-of-an-inch long and can be identified by the rastral (hair) pattern found on the tip of the abdomen using a hand lens. The best time to control grubs is right after egg hatch in late summer / early fall.
Bluegrass Billbugs
Bluegrass billbugs can be responsible for severe trufgrass 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 through the crown and into the root zone, making control difficult. Damage appears as small, brown spots, which may coalesce to form large, brown areas. Dead grass in easily pulled away form the crown, revealing hollow stems with sawdust “frass” present in the chewed areas.
Sod Webworms
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.
Chinchbugs
Chinchbugs feed on turf grass 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 bermudagrass. Adult chinchbugs are about abut one-quarter-inch long with white wings folded over a black body. They remain actively feeding as long as warm conditions prevail, reproducing two to three times per year.
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