Mealybug Infestation on Orchids: Identification and Eradication

White Sticky "Mold" = Mealybugs

Cottony, sticky white patches on stems, leaf centers, and undersides that spread rapidly are mealybugs—not fungus. They suck sap, weaken plants, and vector viruses.

Immediate Treatment

1. Isopropyl alcohol + Q-tips: Touch each bug; white wax dissolves, revealing pink insect.
2. Systemic insecticide (imidacloprid): Apply per label—kills hidden crawlers in media. 3–4 applications weekly.
3. Repeat: Eggs hatch over weeks; persistence is key.

Repotting During Infestation

• Most orchids: Repot late winter/early spring.
• Cattleyas: Wait for new root tips.
• Newly repotted: Warm shade 2–3 weeks, go easy on water.

Prevention

• Quarantine new plants 4–6 weeks.
• Inspect leaf axils, roots, pot rims weekly.
• Alcohol wipe-down monthly as prophylactic.