Borer Damage on Mature Silver Maple

Columbus, OH: 50+ yr silver maple, 4x6 ft bark girdled off, tiny insect holes underneath, orange rusty sap globs on trunk/base. Canopy green/healthy.

Diagnosis: Borer Infestation

• Bore into trunk → wound → bark peels.
• Tiny holes = secondary insects on fungi, not primary problem.
• Orange sap = tree response to injury.

Treatment

1. Spray wound with Merit (kills borers, prevents reinfestation).
2. Remove loose bark (aids healing)—no wound dressing.
3. Fertilize: 10-10-10 at 1 lb/inch trunk diameter (reduces stress attracting borers).

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