Diatomaceous Earth for Japanese Beetles?

Diatomaceous earth can be used to kill Japanese beetles and most other ground dwelling insects. It lodges in the beetles exoskeleton and dehydrates it to death.

Diatomaceous earth kills Japanese beetles quickly, usually within 24 hours after contact. Obviously, it is impossible to apply the powder directly to the foliage plants but it can be applied at ground level and will kill the adults that crawl on it.

Keep in mind that the powder is washed away during the rain so it will possibly need to be reapplied a few times during Japanese beetle season.

Another caveat is that diatomaceous earth only kills the adult Japanese beetles but not the grubs or larva that live underground. In order to kill them, you need to use milky spore powder, which is perfectly tailored to target Japanese beetle larva only.

A big benefit of diatomaceous earth is that it is 100% natural. But it will also kill most other insects that come in contact with it, as well. A combination of milky spore and diatomaceous earth works well at killing Japanese beetles and disrupting their life cycle.