The Japanese Beetle (Popillia japonica) is a beetle about 1.5 cm (0.6 inches) long and 1 cm (0.4 inches) wide (smaller in Canada), with shiny copper-colored elytra and a shiny green top of the thorax and head. It is not very destructive in Japan, where it is controlled by natural enemies, but in America it is a serious pest to rose bushes and other plants. It is a weak flyer and drops several centimeters when it hits a wall. Japanese Beetle traps therefore consist of a pair of crossed walls with a bag underneath, and are baited with floral scent, pheromone, or both.

During the larval stage, the Japanese beetle lives in lawns, where it eats the roots of grass. During that stage, it is susceptible to a fatal disease called milky spore disease, caused by a bacterium called milky spore, Bacillus popilliae. The spores of the bacterium are commercially available in powder form for control of the Japanese beetle.