Japanese Beetles

Japanese beetles (Popillia japonica) were first found in the United States in 1916, after being accidentally introduced into New Jersey. Until that time, this insect was restricted to Japan where it is not a major pest. This pest is considered to be an invasive species. It is now found throughout the eastern U.S., except for Florida, and continues to move westward.

Adult Japanese beetles are approximately 1/3 to 1/2 inch long, have a metallic green head and thorax (the area behind the head) with copper-brown wing covers. The sides of the abdomen have five white patches of hairs, and tip of abdomen has two patches of white hair.

Adult Japanese beetles feed on the leaves, flowers and fruits of many different plants. Preferred plants include rose, grape, linden, apple, crabapple, cherry, plum and related trees, birch, elm, raspberry, currant, basil, Virginia creeper, hollyhock, marigold, corn silks and soybean.

They skeletonize leaves by feeding on tissue between the major veins giving them a lace-like appearance. Damaged leaves turn brown and may fall off.

The larva, or grubs, chew grass roots and reduce the ability of grass to take up enough water and nutrients to remain healthy. When grub feeding is severe, dead patches of grass develop. These dead patches can be rolled back like a carpet due to the lack of roots. If grubs are not found, examine still living turf at the edges of damaged areas for their presence. Moles, skunks, crows and other insect-feeding animals may dig up grubs, further damaging the turf.