Beetles Eating My Crepe Myrtle Tree

Question:

Hardiness Zone: 7a

Maggie from Virginia

Answer:

Adult Japanese beetles are easy to identify. They are about _ inch long and have a metallic green/blue head and body and copper colored wing covers. They like to feed on foliage and flowers, and roses and crape myrtles are two of their favorite plants. From June through August the adult beetles enter the soil to lay their eggs. The eggs hatch into white, comma-shaped grubs that feed on grass roots. As the weather cools, the grubs move deeper into the soil, remaining there over winter. They pupate the following June and leave the soil as adult beetles to start the cycle over again.

There are chemical sprays available for controlling the adult beetles, but I don't recommend them. They harm beneficial bugs like butterflies, bees and ladybugs and are bad for the environment. Your goal should be to disrupt the beetles mating cycle, so for trees, a better method is to purchase a bag trap designed especially for Japanese beetles. These traps are placed about 50 feet away from your tree in June to mid-July and use pheromones to lure the beetles into an hourglass-shaped trap. Once they fly in, they can't fly back out and they die. These inexpensive traps last for 4-6 weeks and are designed to take replacement bags so you can reuse them.

Adult beetles can also be removed by handpicking. Milky spore, Bacillus popilliae, is a disease-causing bacterium that is somewhat effective against Japanese beetles while in the grub stage. Milky spore isn't noticeably effective until the second year of treatment and needs to be applied yearly to remain effective.

Ellen