Understanding and Managing Crape Myrtle Bark Scale

Crape Myrtle Bark Scale (CMBS) is a pest that has been causing significant issues for crape myrtles in the southern United States. Originally from Asia, CMBS was first identified in Texas in 2004 and has since spread to several other states. This pest is a type of felt scale that covers its body with a white, fibrous sac where it lays eggs. The eggs hatch into crawlers, which are pink, grey, or brown, and move around the crape myrtle’s trunk. These nymphs produce large quantities of honeydew, leading to a heavy accumulation of sooty mold on the leaves and branches, making the crape myrtle appear black and unattractive.

Identifying CMBS

To identify CMBS, look for crape myrtles with heavy accumulations of black sooty mold on the leaves, limbs, and trunk. You may also notice patches of small, white felt-like material on the twigs, branches, and trunk, which are close to the size of a grain of rice. Heavily infested twigs may be completely black in color and encrusted with scale.

Seasonal Impact

CMBS is most active during the warmer months, particularly in the spring and summer. This is when the eggs hatch into crawlers and the nymphs produce honeydew, leading to the accumulation of sooty mold. Therefore, it's crucial to monitor your crape myrtles during these seasons and take preventive measures to protect them from this invasive pest

Treating CMBS

The most effective treatment for CMBS is a soil drench with insecticide in the spring and summer. The insecticide will move up into the plants and provide control for at least a year. It is most effective to perform this treatment in the early spring as new growth and the crawler stages begin.

By understanding and identifying the signs of CMBS, and knowing how to treat it, you can help protect your crape myrtles from this invasive pest.