What's eating my alocasia amazonica?

Alocasia × amazonica ('Polly' or 'African Mask') is a popular tropical houseplant and a magnet for spider mites. These thrive in the dry air of heated homes and quickly dull its dramatic dark-green leaves with arrow-shaped white veins. Mealybugs and scale also target the thick petioles. Humidity is your primary defence.

Fine webbing on leaf undersides, pale yellow or grey stippling across the dramatic leaf surface, premature leaf loss Shower the plant weekly, maintain humidity above 60%, apply neem oil or insecticidal soap spray every 5–7 days for a month

White woolly clusters at petiole bases and in the crevices between stem and leaf, honeydew residue Remove with alcohol-soaked cotton swabs, spray with diluted neem oil; quarantine until clear

Brown waxy bumps on thick petioles and leaf midribs, sticky patches, yellowing leaves Scrape off manually, apply horticultural oil spray every 10 days; check petioles carefully as scale camouflages well

Larvae damage fine roots in moist soil, causing wilting; adults swarm around the pot Let the top inch of soil dry out, use yellow sticky traps, and apply a Bti (Bacillus thuringiensis israelensis) soil drench