Return to insects

Japanese beetle (Popillia japonica) is a sporadic, foliar pest of beans. Japanese beetle adults begin to emerge in early June and remain active through early August. They feed on the surfaces of upper leaves that are exposed to full sun. These beetles chew tissue between leaf veins to skeletonize leaves. They are copper and green, ½ inch long, and have tufts of white hairs beyond the wings on the abdomen. While defoliation by Japanese beetle can appear severe, beans can tolerate up to 20% loss of leaves.

Japanese beetle adult.

(Photo: Ric Bessin, University of Kentucky)

Management:

• Monitor plants weekly and use insecticides only as needed to keep defoliation below 20%.
• Do not use Japanese beetle traps.

Return to insects