Crape Myrtle Scale and Aphid Infestation: Black Sooty Mold and Treatment

Crape Myrtle Turning Black? Scale and Aphids Excreting Honeydew

Ladybug-sized bumps on leaves and stems (scale) plus white bugs (aphids) produce honeydew that fuels black sooty mold, turning the whole plant black. Controlling the insects clears the mold.

Treatment Options

Contact Sprays (Thorough Coverage Required)

• Horticultural oil, insecticidal soap, neem oil.
• Pyrethroids (bifenthrin, cyfluthrin, permethrin) – effective but broad-spectrum.
• Repeat in 10–14 days for crawlers.

Systemic Soil Drenches (Best for Large Plants)

• Imidacloprid (Merit, Bayer Advanced) – season-long.
• Dinotefuran (Spectracide Systemic) – faster uptake.
• Acephate (Orthene) – contact + systemic.

Sooty Mold

Once insects are gone, rain washes off the mold. No fungicide needed.

Ant Management

Ants protect honeydew producers. Apply sticky barrier (Tanglefoot) on trunk; use bait stations.

Systemic drench is most practical for mature crape myrtles with dense canopies.