Japanese beetles (Popillia japonica) are small, metallic green beetles that eat away at plants in yards and fields. Large numbers of these pests can strip trees and other vegetation bare quickly. Electronic traps attract beetles by mimicking a tree's honeydew pheromone, tricking them into becoming trapped on sheets of adhesive paper. You can also contain the area around the preferred plant by laying down a thick straw mulch barrier or corrugation plastic to stop the spread of eggs from one plant to another. As an applicator, you can also use BT to protect your garden or yard from Japanese Beetle pest infestations for up to six months during each application.