What's eating my amorphophallus variabilis?

Amorphophallus variabilis, a tropical aroid grown indoors or in warm greenhouses, is most susceptible to spider mites in low-humidity conditions and mealybugs sheltering at the base of its dissected leaf. Aphids can attack new growth. Fungus gnats thrive when the corm's compost stays too wet. High humidity is the best preventive measure.

Fine silky webbing and yellow-bronze stippling on leaf surfaces; foliage loses colour and vigour in dry air Increase ambient humidity; wipe leaves with a damp cloth; spray with neem oil or insecticidal soap every 5–7 days until clear

White powdery colonies at the base of petioles and in crevices; honeydew and sooty mould on leaves Treat with isopropyl alcohol on a swab for visible colonies; spray with neem oil; use imidacloprid drench for persistent infestations

Soft clusters on young unfurling leaves and stems; distorted growth and sticky deposits Knock off with a strong water blast; apply insecticidal soap or neem oil spray; introduce beneficial predators in greenhouse settings

Root damage from larvae in overly wet compost; plant growth slows; adults are a visible nuisance Reduce watering frequency; use yellow sticky traps; apply Bti drench or Steinernema feltiae nematodes to the compost