What's eating my aerangis rhodosticta?

Aerangis rhodosticta is a small African epiphyte with distinctive red column markings on white flowers, grown indoors on mounts or in bark. Scale insects are the biggest threat on its leathery leaves. Mealybugs settle at leaf bases and on aerial roots, and spider mites can establish quickly if indoor humidity is insufficient.

Hard tan or brown discs on both leaf surfaces and aerial roots; sticky deposits and sooty mold; leaf yellowing Scrape off with a soft toothbrush and alcohol; apply horticultural or neem oil spray; treat every 10 days for a month

Fluffy white waxy masses at leaf axils and along aerial roots; plant growth stalls; leaves yellow Remove colonies with isopropyl alcohol on a cotton swab; follow with diluted neem oil spray; isolate from other plants

Pale silvery stippling on leaf surfaces; thin webbing on undersides; most severe in warm, dry conditions Increase humidity; rinse foliage; apply miticide or neem oil spray on a 5–7 day cycle for 3 applications