Oak Tree Weeping Sap: Borer Infestation and Treatment

Diagnosing the Weeping

Fluid oozing from a trunk hole in a Texas live oak with woodpecker holes and ants indicates oak borer activity—likely red oak borer or carpenterworm. The sap is tree's response to tunneling; ants feed on it.

Immediate Treatment

• Spray trunk with Merit (imidacloprid) or Onyx (bifenthrin)—absorbed into bark, kills larvae.
• Soil drench with systemic preferred for full canopy coverage.

Boost Tree Vigor

• Fertilize with 10-10-10 at 1 lb per inch trunk diameter—now and after leaf drop.
• Water deeply during drought.
• Mulch 3 inches to protect roots and trunk base.

Safety Note

If structural decay is advanced (large cavities, fungal conks), consult an arborist for risk assessment near buildings.