Managing Japanese Beetles
You can't miss them. These voracious pests eat and mate in broad daylight and feed on the leaves and flowers of over 300 different types of plants and the roots of turf grass.
Picking the beetles off the plants in the summer as they feed is the most environmentally friendly method of control. Simply pluck the beetles off the plants and drop them in soapy water.
Milky spore disease applied to the lawn kills the larvae of the Japanese beetles. It takes several years for the disease to build up and provide control. In the meantime you can't use other pesticides on the lawn.
Some gardeners find it easier to embrace the damage, calling it "Japanese lace" and give up the fight. Healthy plants can tolerate the damage.
A bit more information: Think twice before putting out Japanese beetle traps. These traps use a pheromone to attract male Japanese beetles and sweet smelling food type bait to attract both males and female. These chemicals are powerful enough to attract thousands of beetles a day. Research has found the traps attract more beetles than they catch. Plus most researchers agree that the traps increase the problem since they bring more insects into the garden rather than reducing the existing population.