Sod webworm is a destructive foliage insect. The adult is a moth measuring one cm that hides in the lawn during the day and comes out during hot nights at the end of May and beginning of June to lay eggs on the lawn. Small caterpillars emerge from hatching eggs. They feed on lawn during the night and hide during the day in the thatch. Caterpillars reach the adult size toward the end of September then hibernate in the thatch. Caterpillars becomes pupae next spring, then adults (moth) to lay eggs in late May and early June. Sod webworm damage is caused by caterpillars that feed on the lawn producing dead patches which could expand to damage all the lawn if caterpillars are in great numbers.