What's eating my crested wood fern?

Crested Wood Fern (Dryopteris cristata) indoors is most commonly targeted by spider mites in low humidity and by mealybugs nesting in the crown. Fungus gnats breed readily in consistently moist potting mix. Scale can occasionally colonize the frond midribs. Good air circulation, appropriate humidity, and careful watering keep this fern largely pest-free.

Tiny pale spots and stippling across frond surfaces; fine webbing on undersides; frond browning and drop Raise humidity with a humidifier or pebble tray; apply insecticidal soap or neem oil spray every 5–7 days for 3 weeks

White fluffy masses in the crown and frond axils; sticky honeydew; distorted or stunted new fronds Remove with isopropyl alcohol swab; spray with insecticidal soap; isolate and re-treat weekly until clear

Larvae damage shallow roots in overwatered soil; small dark flies around the pot; plant loses vigour Let topsoil dry slightly between waterings; use sticky yellow traps; drench with Bti solution for larvae