Mealybug: identify, prevent, control

Updated June 2026

Numbers build in warm weather and stay active year-round under glass, peaking October to April.

Mealybugs are soft sap-sucking insects coated in white waxy fluff that gather in leaf joints and on roots. They weaken plants, drip honeydew that grows sooty mould, and are common on citrus, tomatoes and anything grown under cover.

Citrus mealybug coated in white wax on a leaf — Citrus mealybug (Planococcus citri). Photo: Planococcus citri (Citrus Mealybug), iNaturalist observation 37124896, Katja Schulz, CC BY 4.0, resized, via iNaturalist

How to identify it

Cottony white waxy clusters in leaf joints, stem crooks and under leaves
Sticky honeydew and black sooty mould on leaves below
Yellowing, wilting and stunted growth on infested plants
Ants tending the colonies for honeydew

Black ants tending a crowded colony of mealybugs — Ants tending mealybugs in a lemon tree. Photo: Black Garden Ant tending Citrus Mealybug (15876781048), Katja Schulz from Washington, D. C., USA, CC BY 2.0, resized, via Wikimedia Commons

How to prevent it

Inspect new plants closely, since mealybugs hide in tight crevices
Avoid over-fertilising with nitrogen, which encourages soft growth
Keep ants off plants with a sticky barrier so predators can work
Prune to open up dense growth where mealybugs shelter

Organic control, step by step

Dab colonies with a cotton bud dipped in methylated spirits to dissolve the wax
Spray eco-oil thoroughly into crevices and leaf undersides
Repeat the oil spray every 1 to 2 weeks to catch newly hatched crawlers
Use eco-neem for heavier infestations to disrupt breeding
Release or encourage mealybug ladybirds and lacewings, their main predators
Prune out and bin badly infested growth

Plants it attacks

Grape Custard Apple Aloe Vera Hibiscus

Track it in the app. The free Planting Season planner lists the pests and diseases to watch for on every plant in your garden, tuned to your region.