Japanese Beetle adults and their larvae, commonly called “Grubs” or “Lawn Grubs,” are a serious pest for both lawns and ornamental trees and shrubs. When a Japanese Beetle egg hatches, the young insect that emerges is called a grub. The grubs damage lawns. After the grubs mature, they turn into adult beetles which then feed on trees and shrubs. Between these two life stages, Japanese Beetles can do a considerable amount of damage to a landscape.
Tree & Shrub Damage Caused by Japanese Beetles
In June and July, adult Japanese Beetles emerge from the ground and begin to feed on trees and shrubs. At this point, they are quite similar to college students – all they do is eat, sleep and mate. In the mornings, the beetles feed on a large variety of plants and in the afternoons the females return to the ground to lay their eggs.
The daytime feeding will damage or kill trees and shrubs and the eggs will become grubs that feed on the roots of turf grass and cause damage to lawns.
Some of the more common plants that Japanese Beetles feed on are: roses, linden trees, purple-leaf plums, cherry trees, Japanese maples, Norway maples, beech trees, birch trees, flowering crab apple and many more. Later in the day, the female Japanese Beetles go into the ground to lay eggs. Each female will lay approximately 60 eggs over a 4-6 week period.
How to Control Japanese Beetles
Adult Japanese Beetles that are feeding on your plants need to be controlled as soon as possible. The beetles can do major damage within a short period of time. Green Giant has the people and systems in place to allow us to respond quickly and provide very effective treatments for current infestations.
In the long run, preventative treatments are the best way to protect your plant material from Japanese Beetles. In late winter through spring, Green Giant can provide soil injections that will provide season-long control. With the soil injection, even in years of high Japanese Beetle populations, your trees & shrubs will have at least 95% control
Lawn Damage Caused by Grubs
Grubs are considered sub-surface feeding insects and can cause a lot of damage to turf grass. Learn more about Lawn Grub treatment.