Japanese Beetle is an exotic pest that has been a part of our urban forest for many years. They were first discovered in New Jersey in 19161. They are established and prevalent throughout the United States and feed on numerous types of trees and plants. Lindens are highly preferred, but many other trees are impacted as well.
In our urban forest when beetle populations are high, Lindens are a common tree to be impacted. In July you may notice your linden looking very pale and thin, upon a closer look you will see the damage the adult beetle has done to the leaves. Adult Japanese beetles are defoliators, meaning they feed on the leaves of the tree only ultimately leading to only the veins of the leaves to remain. This type of feeding is called skeletonized feeding. Adult beetles then lay their eggs in mowed turf areas. Those eggs will hatch and the larval stages of the beetles feed and cause damage to your turf grass.
The good thing about Japanese Beetle is that your trees and plants are resilient and typically can handle being defoliated during the growing season and flush out new leaves. Although, year after year of this will stress your plants and trees which could ultimately lead to decline of your tree. An ISA Certified Arborist can best determine if chemical or cultural treatments will be necessary to gain control. Now is the time of year for some of those treatments, so if you notice damage to your trees or plants, make certain to have it checked out and course of action put into place.
- U.S. Department of Agriculture Animal and Plant Health Inspection Service, “Managing the Japanese Beetle: A Homeowner’s Handbook,“, U.S. Department of Agriculture, August 2015.