White Spots on African Violet with Root Rot: Mealybugs or Fungus?

A follow-up question about a plant with confirmed root rot and white spots on stems. The grower wondered if the spots were fungus or mealybugs, and if they caused the root rot.

Distinguishing the Spots

• Mealybugs: Tiny, cottony, may show slight movement under magnification. Alcohol dabbing dissolves them.
• Fungus: Static, powdery or fuzzy, no movement. Alcohol ineffective.

Testing Method

Use a magnifying glass (30x loupe ideal). Dab spots with alcohol-soaked Q-tip. If they dissolve/disappear, they're mealybugs. If unchanged, likely fungal.

Treatment Constraints

African violets are chemically sensitive. Only use products labeled safe for them. For soil mealybugs, treatment is expensive (specialized systemics); often better to propagate clean leaves and discard the plant.

Resource

African Violet Society of America (avsa.org) for current treatment recommendations.