What's eating my primula obconica?

Primula obconica is a cool-season flowering pot plant attacked mainly by aphids, which colonise its soft flower stems and buds. Vine weevil grubs destroy roots and the crown in containers, causing sudden plant collapse. Red spider mite attacks in warm, dry conditions indoors, and slugs damage plants kept outdoors or in cold frames.

Green or grey-white clusters on flower stems, buds, and undersides of leaves; flowers become distorted and a sticky honeydew film coats surfaces. Spray with insecticidal soap or a pyrethrum-based spray, targeting stems and bud clusters; repeat weekly until clear; avoid harsh chemicals on flowers.

C-shaped white grubs eat roots and tunnel into the crown, causing the plant to wilt suddenly and then collapse; adults notch leaf edges at night. Apply nematode drench (Steinernema kraussei or Heterorhabditis bacteriophora) to compost in late summer/autumn; repot and inspect roots if collapse is suspected.

Fine pale mottling on upper leaf surfaces; undersides appear dusty; fine webs in severe cases; worst in warm, dry indoor air. Increase humidity and keep plants cool; apply insecticidal soap or predatory mites (Phytoseiulus persimilis) as a biological control.

Irregular holes eaten through leaves, particularly on outer and lower leaves, with silvery mucus trails left behind. Use copper-ring pot collars; apply iron phosphate slug pellets (wildlife-safe); remove hiding debris around pots; check under pots at night.