This insect is a serious pest of St. Augustinegrass. Damage is mainly caused by southern chinch bug nymphs, which puncture the plant tissue with needlelike mouthparts and suck out the plant sap. This type of feeding causes yellow spots in the lawn that soon turn brown. As the grass dies the chinch bugs move to the edges to feed, causing the dead areas to slowly enlarge.
Damage is usually greatest during hot, dry weather, and in sunny areas rather than in the shade.
High nitrogen levels and thick thatch layers predispose turfgrasses to chinch bug attacks. An easy way of finding these tiny, fast critters is by flushing them out with water. Cut out both ends of a half or one gallon can and push one end down into the yellowed grass at the edge of the yellowed area. Fill the can with water. If chinch bugs are present, adults and nymphs will float to the top within 10 minutes.