Irrigate sunny areas that quickly become hot and dry. Sufficient moisture can suppress chinch bugs. Mow at proper heights. If chinch bug populations become a real threat to the lawn, apply an appropriate insecticide. But don't overdo it, because such treatments often wipe out beneficial insects and those organisms that decompose thatch.
Sod webworms create patches of chewed blades.
If they are present, you may notice webbing in affected areas in the early morning. The worms are the night-feeding larvae of a white to gray moth that deposits her eggs on the lawn in late afternoon or early evening. During the day, the worms burrow into the turf and the layer of thatch. To discourage, rake up dead grass and thatch. After the next mowing, rake again.