What's eating my amorphophallus prainii?

Amorphophallus prainii, a tuberous tropical aroid from Southeast Asia grown as a houseplant or in warm-greenhouse conditions, faces spider mites in dry air and mealybugs sheltering at the base of the single compound leaf petiole. Slugs can destroy the emerging shoot before it unfurls. Fungus gnats breed in wet mix around the tuber. Protecting the single leaf is paramount.

Fine stippling and pale mottling across leaflets; delicate webbing in dry, warm indoor conditions. Increase humidity; spray with neem oil or insecticidal soap targeting leaf undersides; repeat every 5–7 days.

Waxy white cottony masses at the base of the petiole and inside the leaf sheath; stunted or yellowing growth. Apply 70% isopropyl alcohol with a cotton swab to each colony; follow with a neem oil spray; isolate plant.

Ragged damage or total loss of the tender emerging shoot — catastrophic as the plant only produces one leaf. Apply ferric phosphate pellets around the pot before the shoot emerges; check nightly and hand-pick any slugs.

Larvae feed on the feeder roots at the tuber surface in wet compost; adults seen hovering near the soil. Allow the top 5 cm of mix to dry between waterings; drench with Bti; add yellow sticky traps.