The label will tell you everything you need to know about a pesticide. Walk backwards, away from the treated area as you apply insecticides. Control cutworms with sprays of insecticidal soap. White grubs are beetle larvae that feed on grass roots.
Sod webworms create silken tubes in lawn thatch.
Suspect insect pests if you see yellow or brown spots on the lawn. Look for insects both above and below the surface of the soil. If you find insects, send a sample to your county Agricultural Extension Service for identification. Never use chemical insecticides indiscriminately or spray simply because your neighbors are doing so. First you'll need to determine whether you have an insect problem.