How do I get rid of mealybugs on houseplants?

On small infestations, dab visible mealybugs with a cotton swab dipped in 70% (or weaker) isopropyl alcohol, as UC IPM advises. Test it on a small part of the plant 1 to 2 days beforehand to make sure it doesn’t burn the leaves. For wider infestations, UC IPM suggests spraying a 10–25% isopropyl alcohol solution and repeating every week until the infestation is gone. Insecticidal soap, horticultural oil or neem oil can also suppress mealybugs, especially young nymphs. UC IPM notes that imidacloprid spikes or granules may reduce mealybug crawler numbers. Follow the label, and don’t use them on edible plants. Keep the plant isolated from your other plants until no mealybugs remain.

How do I prevent mealybugs?

Inspect new plants thoroughly, including the soil surface and root crown, before bringing them home. Avoid unnecessary nitrogen fertilizer on plants with mealybugs, as UC IPM advises. Check plants regularly so you spot early stages. UC IPM advises checking new plants weekly, then monthly once several weeks pass with no problems.

Pest identification · Pseudococcidae

Mealybugs on Houseplants

Mealybugs are soft-bodied sucking insects covered in a white waxy coating that looks like cotton tufts. They cluster in leaf axils, along stems, and at the base of the plant. Untreated infestations weaken the plant and produce sticky honeydew that attracts sooty mold.

Read the full mealybugs treatment guide

How to identify mealybugs

White cottony masses in leaf axils, undersides of leaves, and where leaves meet stems. Adult females are oval, wingless and about 1/16 inch long (per UW–Madison Extension). Eggs are laid inside the cottony egg sac.

Damage to look for

Yellowing leaves, leaf drop, stunted new growth, sticky honeydew on lower leaves and the pot rim, and black sooty mold growing on the honeydew.

Life cycle (why they spread so fast)

Females of most species lay 100–200 or more eggs in a cottony egg sac over 10–20 days, and there can be two to six generations a year. Crawlers (newly-hatched nymphs) are mobile and spread to nearby plants.

How to get rid of mealybugs

1On small infestations, dab visible mealybugs with a cotton swab dipped in 70% (or weaker) isopropyl alcohol, as UC IPM advises. Test it on a small part of the plant 1 to 2 days beforehand to make sure it doesn’t burn the leaves.
2For wider infestations, UC IPM suggests spraying a 10–25% isopropyl alcohol solution and repeating every week until the infestation is gone. Insecticidal soap, horticultural oil or neem oil can also suppress mealybugs, especially young nymphs.
3UC IPM notes that imidacloprid spikes or granules may reduce mealybug crawler numbers. Follow the label, and don’t use them on edible plants.
4Keep the plant isolated from your other plants until no mealybugs remain.

How to prevent mealybugs

Inspect new plants thoroughly, including the soil surface and root crown, before bringing them home.
Avoid unnecessary nitrogen fertilizer on plants with mealybugs, as UC IPM advises.
Check plants regularly so you spot early stages. UC IPM advises checking new plants weekly, then monthly once several weeks pass with no problems.

Per-species treatment guides

Treatment varies slightly by plant. Find your species below for a dedicated guide.

Source: UC IPM — Mealybugs. Other figures: UW–Madison Extension — Mealybugs and UC IPM — Houseplant Problems, as named in the text.