Japanese Beetle Life Cycle

The adult beetles lay their eggs in late July into August and the eggs hatch shortly after.
Japanese beetle life cycle. White grub phase of the Japanese Beetle life cycle is very destructive to turf grasses. It is not well-thought-out a serious-minded pest in Japan where its natural predators keep populations in avoid. Throughout the summer adult beetles feed on a wide range of plants and deposit eggs in the soil.
Life cycle Japanese beetle grubs spend the winter underground in the soil of lawns pastures and other grassy areas. Japanese Beetle Life Cycle. Adult female beetles lay eggs in the soil in early June.
Adult Japanese beetles prefer to feed in full sun at the top of plants moving downward as the leaves are consumed. Japanese beetles have only one generation per year. Adults may begin to emerge from the soil in early June and are usually most abundant in early summer - from late June through early August.
Japanese beetles are metallic green with coppery-brown elytra hardened front wings and are about a half inch long. Both as adults and as grubs the larval stage Japanese beetles are destructive plant pests. The white oval eggs are usually about 116 inch 15 mm long and 364 inch 10 mm wide.
The life cycle of the Japanese Beetles consists of four stages of development called complete metamorphosis. They will continue feeding until early summer. In late June the first adults emerge with most present in July and August.
Mature beetle grubs become active feeding on turfgrass roots and damaging lawns. Adult beetles are most active on warm sunny afternoons. Adult beetles start to emerge from the ground in late June or early July.