What's eating my amorphophallus abyssinicus?

Amorphophallus abyssinicus is a tropical Amorphophallus species grown in warm outdoor or greenhouse settings. Like other genus members it is most troubled by aphids attacking the petiole and foliage, slugs targeting newly emerging leaves, and in containers by fungus gnats in damp soil. Spider mites can appear under warm, dry greenhouse conditions.

Clustered infestations on the petiole and leaf underside; sticky honeydew and sooty mould. Remove by hand or water jet; apply insecticidal soap or neem oil spray weekly until infestation clears.

Ragged tissue loss on emerging leaves and the petiole base at ground level. Apply iron phosphate pellets; create dry barriers of grit around emerging growth; hand-pick after dark.

Root-hair loss in wet compost; adult gnats hovering at soil surface; young plants may wilt. Reduce watering frequency; apply Bti (Bacillus thuringiensis var. israelensis) drench; use yellow sticky traps.