Japanese Beetle

Adult Japanese beetles are 3/8 inch long metallic green beetles with hard, copper-brown wing covers. Five small white tufts project from under the wing covers on each side, and a sixth pair project at the tip of the abdomen. These white tufts help to distinguish them from similar metallic green or coppery colored beetles.

Adults emerge from the ground in late May or early June. Individual beetles live about 30 to 45 days with activity concentrated over a four to six week period. Beetle numbers begin to decline in late July but some can be found as late as September.

Japanese beetles can feed on about 300 species of plants, ranging from roses to poison ivy. Odor and location in direct sun seem to be very important factors in plant selection. The beetles usually feed in groups, starting at the top of a plant and working downward. While a single beetle doesn't eat much; group feeding by many causes severe damage. Adults feed on the upper surface of foliage, chewing out tissue between the veins. This gives the leaf a characteristic skeletonized appearance.