Brown Spots on alocasia
What's Happening
Spider mites (Tetranychus urticae) feed on Alocasia leaf undersides, piercing cells and causing characteristic stippling - tiny brown spots across leaf surfaces from chlorophyll destruction. These arachnids thrive in low humidity (<50%) and proliferate rapidly in dry indoor environments. The damage appears as scattered brown pinpricks rather than large patches, often accompanied by fine webbing on leaf undersides and stems.
How to Fix It
- 1
Isolate plant immediately to prevent spread to other houseplants
- 2
Inspect undersides with magnifying glass: Look for tiny moving dots (0.5mm) and fine silk webbing
- 3
Wipe all leaves with insecticidal soap or neem oil solution weekly for 3-4 weeks
- 4
Increase humidity to 60-80% via humidifier to create unfavorable mite environment
- 5
Apply miticide if infestation severe - spider mites develop resistance to standard insecticides
How to Prevent It
Maintain 60%+ humidity year-round; quarantine new plants for 14 days; mist plants weekly with water (temporary humidity boost); inspect leaf undersides monthly; group plants to create humidity microclimates that deter mites.