Crepe Myrtle Bark Scale: Atlanta Diagnosis & Treatment Guide

What Is Crepe Myrtle Bark Scale?

Crepe myrtle bark scale is a sap-feeding insect (Acanthococcus lagerstroemiae, formerly Eriococcus lagerstroemiae) that attaches to the bark of crepe myrtle trees and coats the trunk and branches in white or gray, felt-like egg sacs. It is the only known scale that infests crepe myrtle bark, and it was first confirmed in Georgia (Coweta County) in 2014.

How to Recognize It

• White or gray felt-like patches stuck to the trunk, branches, and twigs that look almost like mold or paint flecks
• Black sooty mold coating the bark, leaves, or surfaces under the tree (this grows on the sticky honeydew the scales excrete)
• Sticky residue on the bark or on objects beneath the canopy
• Reduced flowering, smaller blooms, or a generally stunted appearance
• Branch dieback in heavier or long-running infestations
• A ruby pink color when a scale is gently crushed (a quick field identifier)

The scale completes two to four overlapping generations per year in the Southeast, with mobile young (crawlers) typically peaking around mid-May and again in mid-October in our region. The white egg sacs and sooty mold are often most visible in late summer and after fall leaf drop, when bare branches make the infestation easy to spot.

Why It Matters for Atlanta Trees

Damage is largely aesthetic in mild cases, but heavy or untreated infestations can stunt growth, reduce or eliminate flowering, and cause branch dieback. Severe, long-running infestations have been reported to kill entire trees, and the sooty mold that follows the insect can stain hardscapes, vehicles, and structures under the canopy. In Atlanta landscapes, crepe myrtle is the primary host, but the pest has also been documented on American beautyberry, pomegranate, boxwood, and privet, so a single infested tree can put nearby plantings at risk.

General Prevention

• Inspect crepe myrtles regularly, especially the trunk and the undersides of larger branches, so a new infestation is caught before it spreads.
• Plant or relocate crepe myrtles into full-sun locations where possible, since infestations tend to be worse on shaded or stressed trees.
• Inspect any new nursery-bought crepe myrtle before bringing it into your landscape, since the pest spreads easily on infested stock.
• Keep trees healthy with appropriate watering, mulching, and seasonal pruning, since vigorous trees tolerate scale pressure better.

What NOT to Do

• Do not self-diagnose. Many tree problems look alike, and treating the wrong one wastes time and can harm the tree.
• Do not apply fungicides, insecticides, or other chemicals without an arborist's specific recommendation. Wrong product or wrong timing makes things worse, and broad-spectrum sprays can kill the beneficial insects that help suppress scale naturally.
• Do not scrub, pressure-wash, or scrape the bark aggressively to remove the white patches. Crepe myrtle bark is thin and easily wounded, and surface cleaning does not address the underlying infestation.

Related Services

For most diagnosis and treatment questions, the right starting point is one of our services:

• ISA-Certified Arborist Services: diagnosis, consultation, second opinion
• Plant Health Care (PHC): ongoing tree health management
• TRAQ Tree Risk Assessment: when the tree may be a safety hazard

Sources

This page summarizes general information from: UGA Cooperative Extension, UGA CAES Department of Entomology, and University of Florida IFAS Extension.