Japanese Beetle

Description:

Eggs hatch into white grubs with distinct brown heads and three pairs of thoracic legs. Adults are metallic green or greenish-bronze beetles, about 13 mm long with well-developed copperish front wings. They have two patches of white hairs at the tip of their abdomen and five tufts of white hairs on both sides of their abdomen.

Habitat:

This species overwinters as larvae (grubs) in the soil. With the approach of warm spring temperatures, they move toward the soil surface and continue feeding on grass roots. Larvae mature from late May through June and molt to pupae in the soil. Adults emerge from the soil from late June through July. In Pennsylvania adults start to appear about June 20 in the southern areas. They emerge 7-10 days later in other areas of the state. Beetles are most abundant during July and the first two weeks of August. After mating females live 30-45 days and lay 40-60 eggs in the soil. Larvae hatch from the eggs in 10-12 days. They feed on grass roots until late September when cool soil temperatures cause larvae to move downward into the soil to overwinter. They complete their development the next spring. One generation occurs each year.

Notes:

Damage Adults feed on nearly 300 different host plants. Some of the more common ornamental plants include: roses, Rosa spp.; flowering cherry, Prunus spp.; flowering crabapple, Malus spp.; zinnias, Zinnia spp.; Virginia creeper, Parthenocissus quinquefolia ; Boston ivy, P. tricuspidata ; linden, Tilia spp.; birch, Betula spp.; canna, Canna spp.; elm, Ulmus spp.; and marigolds, Tagetes spp. Adults feed during the day, favoring hot weather and plants growing with full exposure to the sun. Adults also consume flowers and foliage of many other host plants. Damaged leaf tissue takes on a skeletonized appearance since they feed between the leaf veins.