Scale on orchid
What's Happening
Armored scale insects (Diaspididae family) attach permanently to orchid leaves, stems, and pseudobulbs, feeding through piercing-sucking mouthparts while protected by a hard waxy cover. Unlike mealybugs, scales do not move once settled and reproduce under their protective shell. The covering makes topical treatments ineffective—alcohol and soaps cannot penetrate. Heavy infestations cause chlorotic spotting, leaf drop, and plant decline as the insect drains photosynthates.
How to Fix It
- 1
Identify scale type: brown soft scale is removable with fingernail; armored scale requires systemic treatment
- 2
For light infestations: dab individual scales with 70% isopropyl alcohol using cotton swab
- 3
For heavy infestations: apply systemic insecticide containing imidacloprid via soil drench per label instructions
- 4
Repeat systemic application every 4-6 weeks during growing season
- 5
Remove heavily infested leaves if treatment fails after two cycles—scales cannot reattach once removed
How to Prevent It
Inspect all new orchids thoroughly before purchase—check undersides of leaves and pseudobulb bases. Quarantine 3-4 weeks minimum. Maintain plant vigor with proper light and nutrition—stressed plants are more susceptible. Apply preventive neem oil monthly during high-risk seasons.