What's eating my sword brake fern?

Sword Brake Fern (Pteris ensiformis) indoors is most commonly troubled by spider mites, especially when air is dry. Scale insects and mealybugs can colonize the stems and variegated fronds. Fungus gnats breed in overwatered soil. The fine, divided fronds make pest detection trickier, so turn fronds over and inspect the undersides at least twice a month.

Stippled pale patches on frond surfaces; fine webbing between frond segments; fronds dry and brown in low humidity Mist fronds and increase ambient humidity; spray with insecticidal soap or neem oil weekly for 3 treatments; rinse undersides

Hard brown bumps on frond stems and midribs; honeydew residue; frond yellowing and early drop Scrape off with a soft brush; apply neem oil or isopropyl alcohol swab; repeat treatment every 7–10 days

White cottony clusters at stem bases and frond axils; sticky surfaces; stunted new growth Remove with alcohol-soaked cotton; spray insecticidal soap; isolate plant and re-treat weekly until clear