What's eating my shingle plant hoya?

Shingle plant Hoya (Hoya imbricata) is a striking epiphyte that plasters its leaves flat against surfaces. Mealybugs and scale insects can shelter in the hidden space between leaf and support, making them very difficult to detect and treat. Spider mites attack exposed leaf surfaces in dry air. Check edges of shingleing leaves regularly.

White cottony residue around the edges of shingle leaves and on stems; honeydew; yellowing and weakened growth Gently lift leaf edges and treat sheltered areas with an alcohol swab; apply neem oil spray along all stem and leaf margins weekly

Brown or tan shell-like bumps on stems and the undersides of flattened leaves; sap loss reduces vigour Manually scrape off scale; apply horticultural oil spray thoroughly, repeating every 10–14 days for a month to catch crawlers

Pale stippling and fine webbing on exposed leaf upper surfaces; leaves look dull and may curl slightly Raise humidity; wipe leaf surfaces with a damp cloth to remove mites; follow with insecticidal soap spray every 5–7 days