Japanese Beetles of Crape Myrtle

Disease Information

Japanese Beetles

Symptoms and damage

Adult Japanese beetles are about ½ inch in length and coppery-brown in color with metallic green heads. They emerge from the soil and feed from May to August. They lay their eggs in the soil. Grubs hatch from the eggs and feed on grass roots. As the weather cools, the grubs move more deeply into the soil, to overwinter.

Both adult beetles and their larvae (grubs) can seriously damage plants as a result of their feeding. Adult Japanese beetles eat flowers and skeletonize leaves (eat leaf tissue between the veins, resulting in a lacy skeleton remaining). The grubs feed on the roots of plants, especially on the roots of grasses.


 Multiple approaches are necessary for controlling Japanese beetles. Adults can be removed by handpicking and destroyed. Japanese beetle traps are available commercially or can be homemade. They may be effective at reducing adult populations.

Keep traps at least 50 feet from the crape myrtle tree or you may create more of a problem by attracting them to the area. Milky spore,Paenibacilluspopilliae, is a disease-causing bacterium that is effective against grubs of Japanese beetles but not the adults. It is commercially available for homeowner use. Many products containing carbaryl, neem oil, cyfluthrin, permethrin, lambda cyhalothrin or acephate are labeled for use by homeowners against Japanese beetles on crape myrtle. Soil drenches of imidacloprid in the spring will control Japanese beetles and last longer within the plant to prevent future infestations by additional pests .



Share this article