In the early spring they move up, as the soil warms, to feed and to complete their development. The grubs pupate to adults and emerge from the ground in late spring and early summer. Most species complete their development in a year while some may require two or three years. Grub injury causes the turf to turn brown in large irregular patches that can be pulled up and rolled back like a carpet, usually exposing the grubs. These are one of the most important pests of lawns, especially in the warmer parts of the state.
Adults are black with pearly-white wings.
During the winter the adults hibernate in lawns, under fallen leaves and other protected places. In the spring, adults migrate to lawns and lay their eggs at the base of grass plants. The eggs hatch into tiny nymphs in about a week. Most of the damage is caused by nymphs which suck the plant sap from the grass stems. Damage first appears as small yellow or brown areas that increase in size and coalesce as the injury progresses.