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Entomology: Landscape Pest Management: Insect ID : Ornamentals

Japanese Beetle (Po;illia japonica)

Japanese Beetle Adults

Japanese Beetle (Popillia japonica)

Adults are nearly ½ inch long, broadly oval, thick bodied, with coppery grown wing covers and a metallic green body. Mature larvae are nearly 1 inch long and white, with brown heads. They resemble several other scarab beetle larvae, but may be identified by the shape of the raster (an area of bare spots, hairs, and spines on the underside of the last abdominal segment). There is one generation a year. Larvae overwinter in soil.

Adults of this imported scarab beetle feed on the flowers and leaves of many plants. Preferred plants include rose, crapemyrtle, maples, sycamore, birch, cottonwood, linden, mountain ash, and elms.

Look for adults on preferred hosts from early June through August. Weekly application of residual or contact insecticides to host plants in June through July will provide only partial adult control. Traps usually are counterproductive and most often call in more beetles than they trap. Use traps to time insecticide application for adults. Do not use traps for control.

Japanese Beetle trap