What's eating my natal plum bonsai?

Natal Plum bonsai (Carissa macrocarpa), grown as a tropical houseplant or warm-climate bonsai, is susceptible to scale insects, mealybugs, and spider mites — all classic indoor/tropical pests. Its thick, waxy leaves and dense thorny structure make colonies hard to spot. Scale is the most damaging and persistent threat.

Brown, waxy bumps along stems and leaf midribs; produces heavy honeydew that leads to sticky leaves and black sooty mould Scrape off visible scales with a cotton swab dipped in rubbing alcohol; apply horticultural oil or neem oil spray; repeat every 10 days for 3 cycles

White cottony clusters in leaf axils and at branch nodes; sap removal weakens growth and promotes sooty mould Dab individual colonies with a 70% isopropyl alcohol swab; drench growing medium with diluted neem oil; inspect undersides of leaves weekly

Fine tan or bronze stippling on leaves, visible webbing on undersides in low-humidity indoor conditions Wipe leaves with a damp cloth; increase humidity; spray with insecticidal soap or neem oil, focusing on leaf undersides; repeat every 5 days