The beetle species Popillia japonica is commonly known as the Japanese beetle. It is about 1.5 cm (0.6 inches) long and 1 cm (0.4 inches) wide, with iridescent copper-colored elytra and green 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 of about 200 species of plants, including rose bushes, grapes, hops, canna, crape myrtles, and other plants.
It is a clumsy flier, dropping 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. However, studies done at the University of Kentucky suggest that traps attract more beetles than they actually trap, thus causing more damage than may have occurred were the trap not used.
These insects damage plants by skeletonizing the foliage, that is, consuming only the leaf material between the veins.
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