What's eating my kaffir lime?

Kaffir lime (Citrus hystrix) is a true citrus and susceptible to the full range of citrus pests. When grown as a container herb or houseplant, spider mites and scale insects are the most common threats. Citrus leafminer mines new flush growth. In outdoor citrus-growing regions, Asian citrus psyllid is a critical biosecurity risk.

Waxy or shell-like bumps on stems and leaf undersides; suck sap causing yellowing, leaf drop, and sticky honeydew that promotes sooty mould. Scrape off manually; apply horticultural oil or neem oil to smother crawlers. Repeat every 7–10 days. Isopropyl alcohol on a cotton swab for small infestations.

Fine pale stippling on upper leaf surfaces; webbing on undersides; leaves yellow and drop. Worst on indoor or greenhouse-grown trees in low humidity. Increase humidity; spray undersides with water daily. Apply neem oil or insecticidal soap. Introduce predatory mites (Phytoseiulus persimilis) for persistent infestations.

Larvae tunnel serpentine trails through new flush leaves, causing them to curl and distort; damage is mostly cosmetic but weakens young trees. Time any pruning to avoid stimulating new flushes during peak adult moth activity. Spinosad spray on new growth flush if trees are young and heavily affected.

Feeds on new growth, causing twisted distorted leaves and waxy white tubules. Transmits citrus greening disease (HLB), which is fatal to the tree. Report to plant health authorities immediately if found — it is a notifiable pest in many regions. Remove and destroy infested flush. Do not move affected plant material.