Scale Insects on Air Plants
Air Plant (Tillandsia spp.)
Symptoms
- small brown or tan bumps along the leaves
- bumps fixed in place that a fingernail can't easily dislodge
- sticky honeydew residue near the base
- yellowing or weakened leaves near heavy infestations
Causes
Scale insects feeding on leaf tissue
Scale insects attach to the plant's leaves and feed on the same tissue that would otherwise be absorbing water through its trichomes, feeding on the plant's limited internal moisture and nutrient reserves through a protective waxy covering.
Introduction from a nearby infested plant
Scale spreads slowly on its own but establishes when an infested plant is displayed close to a healthy one.
Low natural predator presence indoors
Indoor environments lack the natural predators that keep scale populations in check outdoors, allowing an initially small infestation to grow unnoticed for weeks.
How to Fix It
- 1
Isolate the plant to prevent scale from spreading to nearby plants.
- 2
Gently scrape off visible scale with a fingernail or soft toothbrush, being careful not to damage the delicate leaf surface and trichomes.
- 3
Wipe remaining scale with a cotton swab dipped in diluted rubbing alcohol.
- 4
Follow with a light application of horticultural oil or diluted insecticidal soap, using a lighter hand than you would on a rooted plant since this species absorbs through its leaf scales rather than roots, and plan on repeat treatments roughly weekly for the next several weeks.
- 5
Rinse the plant gently during its next soak to help remove any residue from treatment.
Prevention
- Inspect leaves regularly, checking closely along the length of each one
- Quarantine new plants before displaying them near an existing collection
- Check leaves individually rather than glancing at the clump as a whole, since a single air plant's dense leaf overlap hides early bumps easily
Quick Summary
| Plant | Air Plant (Tillandsia spp.) |
|---|---|
| Category | Pests |
| Likely causes | Scale insects feeding on leaf tissue, Introduction from a nearby infested plant, Low natural predator presence indoors |
| Fix steps | 5 steps — see above |