What's eating my diascia 'wink coral pink'?

Diascia 'Wink Coral Pink' is a compact container series most bothered by aphids on its flower stems and whitefly in warm sheltered spots. Slugs are a persistent threat in cool damp conditions early in the season. Vine weevil root damage is a known risk in patio pots kept over multiple seasons.

Colonies on young shoots and buds; honeydew leading to sooty mould; reduced flowering and leaf curl. Spray with insecticidal soap or neem oil; repeat every 5–7 days. Encourage parasitic wasps by planting umbellifers nearby.

Ragged holes in foliage and stems; damage worst at plant base after rain or irrigation; slime trails present. Apply iron-phosphate slug pellets; use copper tape on pots; hand-pick at night. Remove hiding spots such as dead leaves.

Plants collapse without explanation; C-shaped cream grubs in the root zone eating fibrous roots. Drench compost with Steinernema kraussei nematodes in late summer. Inspect roots when repotting and destroy any grubs found.