What's eating my begonia × tuberhybrida 'pin-up flame'?

Begonia × tuberhybrida 'Pin-Up Flame' produces large, bicoloured blooms that are attractive to thrips, which leave visible silvering on petals. Vine weevil larvae are the most destructive threat, targeting tubers and roots. Slugs damage fleshy foliage at night. Proactive nematode treatment in containers protects the tuber through winter.

Grubs feed on tubers and roots below soil level, causing sudden wilting and plant death; adults make characteristic notches in leaf margins at night. Water in nematodes (Steinernema kraussei) to moist compost from late summer through early autumn; dig out and inspect tubers; repot into gritty, well-drained mix.

Ragged holes in leaves and petals, slime trails at the base; fleshy stems may also be gnawed at ground level. Hand-pick at dusk; set beer traps; apply iron-phosphate slug pellets; use copper tape barriers on containers.

Silvery streaks and deformed patches on the large, decorative blooms; petals may look papery or distorted. Remove affected flowers; spray neem oil or spinosad, covering blooms thoroughly; use blue sticky traps near the plant.