What's eating my black tree fern?

Black Tree Fern (Cyathea medullaris), a striking large tropical, is most often attacked by scale insects on its distinctive black stipes and trunk. Mealybugs shelter in the crown. Spider mites colonise fronds in dry conditions. Grown outdoors in suitable climates, caterpillars and slugs may target the soft emerging croziers.

Hard brown or cream shells on the black stipes and frond undersides; fronds yellow and honeydew accumulates Scrub stipes and trunk with insecticidal soap solution and a brush; apply horticultural oil spray; repeat every 3–4 weeks

White cottony tufts at the crown and lower frond bases; general loss of vigour and sticky deposits Blast off with a water jet; follow with neem oil spray every 7–10 days for 4 weeks

Fine silvery stippling on frond surfaces; webbing under leaflets; fronds bronze and shrivel in dry air Raise humidity, shower fronds thoroughly, and apply insecticidal soap or neem oil weekly

Ragged holes or entire sections chewed from soft croziers and young fronds Hand-pick caterpillars; use Bt spray for caterpillars; apply iron phosphate pellets for slugs around the trunk base