How and what do you use to deter Japanese beetles from damaging young grapes as they come on vine in early spring

Answer #1 · Gardenality.com's Answer · In Japan, where the Japanese beetle originally comes from, this insect is not a big problem. The reason why is because there are natural predators that feed on the Japanese beetle grubs; those small white curled grubs you might find when digging in your landscape or garden.

When it comes to controlling Japanese beetles there are two basic methods you can use. You can control them organically or with chemical insecticides.

There are many chemical insecticides you can use to control and eliminate Japanese beetles, but probably the most effective and least toxic is Carbaryl (Sevin) that is available in liquid or dust form. This chemical is best applied to plants when they are above ground.

For organic gardeners, you can control Japanese beetles several ways. Putting out traps containing a pheromone that attracts the female, and a floral lure that attracts the male, are quite effective. Some say this will attract your neighbors beetles to your garden. I don't see this as a negative thing. Any trapped beetle is a good beetle. If your neighbors aren't doing anything to control the beetles, you might as well get there's as well. If you don't these beetles will go back into the ground - after mating above ground - to lay larvae (eggs) that will cause you problems next year. So, in my opinion there is no disadvantage to using traps.

You can also use physical and biological methods to control the grubs while they're in the ground. You can use nematodes or Milky Spore(Bacillus popilliae). The two nematodes that are most effective against Japanese beetle grubs are Steinernema glaseri and Heterorhabditis bacteriophora. Both these nematodes are commercially available though you might have to get your local nursery and garden center to order them for you. Milky Spore (Bacillus popilliae), a naturally occurring host specific bacterium, will also attack the white grubs.

Hope this information helped.)