Scale Insects on Meyer Lemon: Sticky Leaves, Brown Bumps, and How to Save Your Tree

Identification

Sap on leaves and small brown spots = scale insects. Adults: oval/round, 3–5 mm. They excrete sticky honeydew. Juveniles: tiny, white, cottony, mobile.

Treatment Options

Small Tree / Light Infestation

• Scrub adults with old toothbrush + soapy water.
• Dab juveniles with 70% isopropyl alcohol on swab.

Heavy Infestation

• Horticultural oils (summer oil, Volck oil) — smother insects. Follow label precisely; concentration depends on temperature.
• Insecticidal soaps for crawlers.

Key Point

Controlling the scale eliminates the honeydew, which in turn starves the sooty mold (black fungus) that may develop.