As the soil temperatures warm in the spring they move up to the grass roots, feed for a short time, pupate, and merge as adult beetles to begin a new cycle. Feeding in the spring is not as destructive as it is in the fall and only requires an insecticidal treatment. Phyllophaga grubs require three years to complete their life cycle. Adults are active in the spring, usually from late May until early July. Eggs are deposited by adults in the soil and hatch in a few days.
Small grubs feed during the first summer, moving down in the soil to overwinter.
The second summer they feed vigorously, casing severe damage, then move down in the soil profile to overwinter the second winter. They complete feeding the third year, overwinter as adults and emerge the following spring to complete the life cycle. Early symptoms include wilting and tan discoloration similar to moisture stress. Dead patches are small at first, but enlarge as grubs grow and expand their feeding sites. Turf may die as a result of the destroyed root system unless soil moisture is maintained to encourage regrowth from the crowns.