Mealybugs on Phalaenopsis: Identification & Three-Step Treatment

White Fluffy Patches on Orchid? It's Likely Mealybugs

Cottony white masses on stems and leaf undersides are mealybugs—sap-sucking insects that weaken plants and spread viruses. They hide in crevices and root zones, so surface cleaning alone fails.

Three-Step Eradication

1. Physical removal – Swab visible bugs with 70% isopropyl alcohol on cotton swabs.
2. Systemic insecticide – Unpot, wash all old media off roots, spray entire plant with a systemic labeled for orchids (e.g., imidacloprid or permethrin products).
3. Repot in fresh mix – Discard old media, clean pot thoroughly, repot in fresh bark. Remove any mushy roots.

If Plant Is In Bloom

Delay full treatment until flowers fade. Meanwhile, swab visible bugs weekly with alcohol. Systemics can be applied carefully to avoid flower damage.

Prevention

• Inspect new plants before introducing
• Quarantine 2–3 weeks
• Check leaf undersides monthly
• Repot annually to disrupt pest cycles