Sooty Mold on Muskogee Crape Myrtle: The Real Culprit Is Aphids

Yellow Leaves, Black Spots, and Wasps? It's Sooty Mold from Aphids

Your Muskogee crape myrtle's yellowing, black-spotted leaves, premature leaf drop, blackened branches, and swarms of large black wasps all point to one thing: sooty mold growing on aphid honeydew.

The Chain Reaction

1. Aphids feed on plant sap and excrete sticky, sugar-rich honeydew.
2. Sooty mold (a black fungal coating) grows on the honeydew, blocking sunlight and weakening the plant.
3. Wasps and ants are attracted to the honeydew — they're not attacking the tree, just harvesting the sugar.

Control the Aphids, Eliminate the Mold

Once aphids are gone, the honeydew stops, and sooty mold weathers off naturally. Effective options:

• Systemic insecticides like acephate (Orthene, Isotox) move through the plant and kill feeding aphids.
• Soil-applied systemics like imidacloprid (Bayer Advanced Tree & Shrub, Merit) are drenched around the root zone for season-long control.

Quick Tips

• Treat early — before mold spreads to nearby plants.
• Follow label rates and timing exactly.
• Expect wasps to disappear once their sugar source is gone.

Your crape myrtle will rebound once the aphid infestation is broken.