Alocasia 'Polly': Spider Mites, Mealybugs, or Mildew?

Diagnosing White Powdery Spots and Leaf Dieback

After washing dusty leaves, an Alocasia 'Polly' developed spots, dying leaves, and white powder on leaf undersides that returned after detergent washing.

Possible Causes

• Red spider mites: Suck sap, leave fine white webbing between leaves/stems.
• Mealybugs: Tiny insects covered in white cottony fluff on stems and leaf undersides.
• Mildew: Fungal; needs fungicide.

Treatment

• If insects recur after washing, apply appropriate insecticide.
• If mildew, spray fungicide; remove badly affected leaves.
• Provide high humidity, bright indirect light, moist (not wet) soil, no drafts. Clean leaves often.
• If all leaves die, keep shady, water occasionally, await new growth—Alocasia often goes dormant.