The pupae are light yellowish-brown in color and have prominent legs. They measure about 0.63 inches in length. Adult rose chafers become active in northeastern North America from late May to early June. The adults appear suddenly. It seems as though the entire population reaches maturity practically at the same time, and multitudes of beetles suddenly make their appearance.
Beetles feed and mate soon after emerging from the soil.
It is common to see mating pairs in the newly formed grape clusters. Mating and egg laying occur continuously for about two weeks with each female depositing 24 to 36 eggs. The average life-span of the adult is about three weeks. Approximately two weeks after being deposited, eggs hatch into tiny, white, C-shaped grubs. The larvae feed on the roots of grasses, weeds, grains, and other plants throughout the summer, becoming fully developed by autumn.