Japanese beetles feed on a number of common shade trees, shrubs, woody ornamentals, fruit and vegetable plants. They can most often be found on birch, Japanese maple, purple plum, linden, cherry and crape myrtle in Bucks and Montgomery County. The adults are 3/8" long with a metallic green head and thorax, and copper-brown wing covers. The larvae are white, C-shaped grubs 1/16-1/4" long. They overwinter in the soil. In the spring they feed on the roots of turf until emerging in late June, early July as beetles. They are most actively feeding on foliage through July and early August. Heavy infestation of this insect can cause complete defoliation, and in some cases, death of the host.
There are a variety of pesticides which may be sprayed or soil injected for control of Japanese beetles. The species of the tree or shrub, as well as the bloom time, must be considered when choosing the appropriate method of control. Proper planning for treatment is suggested if the threshold of acceptance is low for leaf damage. A combination of soil injections and foliar spraying may be necessary in areas of severe infestations.
Contact Plant Health Solutions for proper diagnosis and to develop a treatment plan.