pests on Calathea
Quick answer
If your Calathea has pests, the most likely cause is: Spider mites (Tetranychidae) and thrips (Thripidae) are the primary pests affecting Calathea, thriving in hot, dry conditions that stress the plant. Spider mites cause stippling—tiny yellow or white dots on leaves—while thrips leave silvery patches and black frass. Both pests feed on leaf sap, weakening the plant and causing distorted new growth. Low humidity (<40%) exacerbates infestations by creating favorable conditions for these pests while simultaneously stressing the plant's defenses.
Start here:
- 1. Isolate infested plant immediately to prevent spread to other houseplants
- 2. Shower leaves thoroughly with lukewarm water, paying special attention to undersides where pests hide
Why Calathea gets pests
Goeppertia spp.
Spider mites (Tetranychidae) and thrips (Thripidae) are the primary pests affecting Calathea, thriving in hot, dry conditions that stress the plant. Spider mites cause stippling—tiny yellow or white dots on leaves—while thrips leave silvery patches and black frass. Both pests feed on leaf sap, weakening the plant and causing distorted new growth. Low humidity (<40%) exacerbates infestations by creating favorable conditions for these pests while simultaneously stressing the plant's defenses.
How to reverse pests on Calathea
- 1
Isolate infested plant immediately to prevent spread to other houseplants
- 2
Shower leaves thoroughly with lukewarm water, paying special attention to undersides where pests hide
- 3
For spider mites: Increase humidity immediately and spray with neem oil or insecticidal soap every 5-7 days for 3-4 weeks
- 4
For thrips: Apply spinosad (Captain Jack's Dead Bug Brew) every 7-10 days for 3-4 cycles—thrips are resistant to neem oil alone
- 5
Use yellow sticky traps near the plant to catch adult flying thrips and monitor infestation levels
- 6
For severe infestations: Apply systemic insecticide (imidacloprid) as soil drench—follow label instructions carefully
- 7
Treat ALL nearby plants preventatively even if they show no symptoms—pests spread rapidly
- 8
Continue monitoring for 6-8 weeks as eggs hatch and lifecycle continues
Keep pests off this Calathea
Maintain 50-60%+ humidity to create unfavorable conditions for pests. Inspect new growth weekly with a magnifying glass—early detection is critical. Quarantine new plants for 2-3 weeks before introducing to collection. Shower plants monthly to dislodge pests and eggs. Avoid over-fertilizing with nitrogen, which attracts sap-sucking pests.