Black Ooze on Cycad Seed Cones: Fungus, Insects, or Sap?

The Observation

A 15‑20 year‑old female cycad has black, thick ooze on leaves surrounding the seed cones, gluing them shut. No insects seen.

Possible Causes

• Sooty mold on honeydew: Check for scale insects on cone scales and leaf undersides.
• Plant exudate from borer injury: Look for small holes or frass near the cones.
• Fungal colonization of sugary secretions: Cycads sometimes produce nectar‑like fluids that fungi colonize.

Next Steps

1. Inspect thoroughly with a magnifier for scales or borer holes.
2. Try rinsing with a strong water jet—if it washes off, it’s likely exudate or honeydew.
3. If scales found, treat with horticultural oil or systemic insecticide.
4. Send a close‑up photo if unsure.