Japanese beetles often ruin flowers. You can remove the beetles from your garden with a natural pesticide repellent. Before you make a repellent for the beetles, you will need to take precautions to protect yourself from the invasive beetles. Since Japanese beetles enjoy diseased plants, you will want to remove any dead and diseased wood and shrubs. Dead and dying grass will also attract the beetles, so it is best to keep your yard healthy during the growing season.
Kill the beetles in your garden. Capture them in a jar that contains soapy water and seal it tight.
Add 1/4 cup of dish detergent soap to a 1-gallon bucket. Fill the bucket with warm water. Once you capture and kill about 10 Japanese beetles, place them in the dish soap solution.
Place the bucket in your garden, close to where you normally have infestations. This will warn the other Japanese beetles. They will follow the scent markers and realize that the feeding ground is poor quality. Leave the bucket in your garden for two weeks. The soap in the water will keep mosquitoes from laying eggs.
Plant rue and garlic plants together in your garden. The scent repels them.
Make a homemade beetle trap. If you do not want to capture the beetles, and want to avoid growing more plants in your garden, then you can make your own trap with a few basic ingredients. Simply dissolve 1/4 cup of sugar and 1 package of yeast into 1 cup of water. Add a mashed banana to the water and mix well. Pour this mixture into an empty milk jug, and leave the top off. Place this in an area where the Japanese beetles typically feast.