japanese beetles

Asked July 1, 2017, 10:10 PM EDT

How can I get rid of Japanese beetles? Is there any thing that I can buy at the store or make at home to spray on my plants? The Japanese beetles are eating all the leaves on my strawberry plants, hops vines, grapevines, pumpkins, and the new cherry trees I just planted this year. The beetles are really bad this year. They normally eat my hops and grapes every year but this is the first year that they are eating my cherries, pumpkins and strawberries.

Westmoreland County Pennsylvania

1 Response

I don't know if you are familiar with row cover or low tunnels. Low tunnels are PVC conduit bent into hoops that go over your vegetable or fruit. Then a very light filmy row cover for sale at places like Johnny's Seeds is installed over the hoops and held on with clips. The beetles can't get through the row cover. If you look at Johnny's seeds online, they have instructions for creating a low tunnel, and they sell the fabric.
When you are ready, you want to knock off as many beetles as possible. If it won't damage your fruit, you can spray the infested plants with a sharp hose spray to knock off the beetles. You can also shake the plants. You want to kill as many as possible, and wash off their eggs. You could also use an insecticidal soap in a hose sprayer.
Once the beetles are dealt with, erect the barrier and make sure you use flat boards to hold down the sides. In hot weather you will have to ventilate by opening the ends.
Then plant a trap crop of something the beetles like. Here is a link to an article on trap crops for Japanese beetles. Finally, there is a biological control for the grubs called milky spore. Here is a link to an article on managing Japanese beetles.
For the cherry trees, you most likely will have to spray. There are a variety of products that list Japanese beetles on the label.
If you try this method of exclusion described above, you can set it up year to year before the beetles get started and take it down when the adults disappear. The milky spore will kill any grubs in the soil. Although Japanese beetles fly long distances to find their favorite food, they will encounter your trap crop before they find your vegetables and fruit. Of course, you will need to keep killing them at the trap crop until the adults disappear.