What's eating my alocasia?

Alocasia is most commonly attacked by spider mites, which thrive in the dry air typical of heated homes. Mealybugs and scale appear on petioles and corms. Fungus gnats exploit the moist soil Alocasia prefers. The large leaf surfaces make spider mite damage — pale, dusty stippling — very visible and alarming.

Pale dusty stippling across entire leaf face; fine webbing at petiole bases; leaves yellow and drop in severe cases Shower the plant to knock off mites; apply neem oil or insecticidal soap to upper and lower leaf surfaces; raise humidity; repeat every 5–7 days for three cycles

White waxy colonies at petiole bases and on corms when repotting; yellowing, weak new growth Dab with isopropyl alcohol; spray with insecticidal soap; inspect and clean corms during repotting; isolate from other plants

Adult gnats swarm around soil; larvae damage fine roots, causing wilting and yellowing despite wet soil Allow top 2–3 cm of soil to dry between waterings; use Bacillus thuringiensis israelensis (Bti) drench; sticky traps for adults; top-dress with grit