My husband put dish soap and water into a spray bottle - kills the Japanese Beetles! Just rinse your plants off.
Once you see a few... each day - start the 'watch'... as they mate they give off a phermone and more come. We start seeing them in the afternoon at the heat of the day.
A few spray - I even scraped them into a small jar with soapy water and they die! Then I keep checking my plant where they landed off and on for about 2-4 hours and then 'they' are gone for a day or so. This is particularly true with my Hydrangea tree.
Agree! I had a cut off a clean milk jar still with the handle with soapy water and flip the beetles into the jars. After I got a lot of them, I used the soapy water to spray the roses and most of the beetles do not come any longer. Read it somewhere and it has worked for me.
I saw this from http://dkmommyspot.com/the-continuing-story-of-natural-remedies-for-japanese-beetles/
I just came up with a concoction today that got rid of a lot of them. I took a 1 1/2gal. chapin sprayer, filled it with warm water, about 3 tsp of garlic powder, 2 tsp of cayenne pepper, a couple of squirts of dish soap and a little under a 1/4 cup of vegetable oil. Shook at and sprayed the little buggers really good. They didnít like the smell, if they eat the leaf, it is hot, and the oil and soap stick to the plant. It doesnít smell too good, but it worked.
another said 1/4 cup for 1 gallon.
there is also this info:
A few drops of soap in a gallon of water can be sufficient. Adding a few drips of oil helps the soap stick to the plant and continue to kill insects. For spraying plants indoors, adding 1 tsp. to a hand sprayer of water is recommended. Some plants such as sweet pea and some tomato varieties are harmed by contact with soap. Use a diluted solution and test one plant a few days before doing a general spraying. Repeated applications may be necessary for a heavy infestation of insects to be eradicated.