If you are trying to get rid of Japanese beetles, you can do it with a variety of different methods. Chemical methods, natural methods, and traps may all be effective. There are also several preventative measures you can take to prevent their recurrence on your land.
To get rid of Japanese beetles using chemical control, you may benefit the most from insecticides containing pyrethroid or carbaryl. There are many different brands on the market that contain both of these ingredients. Spraying insecticides containing either of these chemicals on your lawn, garden, or any other area affected by Japanese beetles should provide at least a few weeks of protection before they return. Repeat applications will likely be necessary before the bugs cease to be a problem. Always follow the instructions on any insecticide you use to ensure your safety, and check to be sure that it is safe for use on your specific plants and flowers.
People who do not want to use chemicals to get rid of Japanese beetles may have success with natural remedies. The most effective natural products on the market for eliminating Japanese beetles typically contain neem or pyola. Neem is a natural pesticide derived from the Azadirachta indica plant, and pyola comes from pyrethrins present in canola oil. Using natural products containing either of these two ingredients typically keeps Japanese beetles away for three days, at the most. There is a very good chance repeat applications will be needed before the Japanese beetles are gone for good.
Other options available to get rid of Japanese beetles include traps or manually removing them by hand. The traps work by emitting scents, such as food or pheromones, to attract the beetles. To get the best results, it may be beneficial to use the traps along with some type of insecticide because some people claim they don't catch many beetles. Hand removal of beetles is normally effective, but in most cases it only works well if there isn't a large infestation. If the problem is limited to a few potted plants rather than the entire lawn or garden area, picking the beetles off every day until they stop coming back may be a successful method of removal.
Even if the adult Japanese beetles have been eradicated, it is likely that they have left eggs, or grubs, in the ground. These grubs will grow into adults after about six weeks of living in the soil, feeding on the roots of grass and other plants. There are products containing bacteria called Bacillus popilliae under different brand names that should effectively eliminate grubs from your lawn. Many garden centers also sell beneficial nematodes, or worms, that you can spray directly on your lawn to kill grubs. These worms are not considered harmful to humans or plants, and are not supposed to be a threat to any beneficial lawn insects.
Prevention is one of the most important things to consider if you want to get rid of Japanese beetles. Even if you get rid of them one year, they may return the next. Keeping your soil healthy by adding mulch to the topsoil yearly may keep beneficial insects around that prey on grubs. It might also be helpful to feed birds throughout the year and not just during one or two seasons. They eat Japanese beetles and grubs and could help prevent and control your problem.