How to Prevent Japanese Beetles From Laying Eggs

Controlling Adults

• 1

  Inspect your fruits, vegetables, landscape plants and other trees and plants for adult beetles in early June. The adults rise from the ground at this time and begin mating and laying eggs almost immediately.

• 2

  Shake off adult beetles into the bucket of soapy water as soon as you see the first adults on your plants. The soapy water will drown them and prevent them from releasing a pheromone that attracts other adults from miles away. You can also touch adult beetles with one finger; they freeze and fall when you do so.

• 3

  Apply one of many insecticides labelled for Japanese beetle control or prevention. These products will force the beetles to move onto areas with greater food choices.

• 4

  Keep your soil as dry as possible during June and July; adults lay eggs during this time and search for lush, green lawns that will feed their larvae well.

Controlling Eggs and Grubs

• 5

  Withhold irrigation to your lawn during adult flight times -- early- to mid-summer. Even if the adults have laid eggs already, the eggs will struggle to survive in relatively dry soil.

• 6

  Release nematodes or other biological controls onto your soil where beetle or grub activity is present. Although slightly inconsistent, the parasitic nematodes will help control the white grubs in the lawn.

• 7

  Apply an insecticide labelled for Japanese beetle grub control onto your lawn. Carbaryl, diazinon and trichlorfon are all acceptable and effective insecticides for this use.