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Crepe Myrtle Borers: White Powder and “Worms” on Trunk

Frass Tubes on Crepe Myrtle = Borer Infestation

The white powdery substance falling and the stationary white “worms” protruding horizontally from the trunk are borer frass (sawdust-like excrement) packed in exit holes. The insects are inside.

Treatment

Spray the trunk and all frass tubes with Merit (imidacloprid) or Bayer Advantage insecticide.
Reapply if new frass appears.

This kills larvae under the bark. Keep the tree vigorous with proper watering and fertilization to deter future attacks.

Trees: Crape Myrtle Powdery Mildew: Fungicides and Pruning Advice; Diagnosing a Single Ailing Crepe Myrtle Among Healthy Ones; Replacing Willows with Crepe Myrtles: Choose Aphid-Resistant Varieties; Spider Mites on Crape Myrtle: Sticky Residue, Curling Leaves, and Webbing; Transplanted Crepe Myrtle Oozing in Texas Heat: Root Shock; Controlling Crepe Myrtle Suckers Without Weed Whacking; Crepe Myrtle Care: Fertilize Spring, Prune Late Winter; Crape Myrtle Aphid Battle: Persistence Beats Sooty Mold Sprays; Transplanting a Mature Crepe Myrtle in SE Pennsylvania; Puppy-Pruned Crepe Myrtle: Fence It, Expect Fewer Blooms

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