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.
How to identify mealybugs
White cottony masses in leaf axils, undersides of leaves, and where leaves meet stems. Individual adults are 2–3 mm, oval, pinkish-white. 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)
Egg to adult in ~30 days indoors. Females lay 300–600 eggs inside the cottony mass. Crawlers (newly-hatched nymphs) are mobile and spread to nearby plants.
How to get rid of mealybugs
- Dab visible mealybugs with a cotton swab dipped in 70% isopropyl alcohol — the alcohol dissolves the wax and kills on contact.
- For wider infestations, spray the whole plant with insecticidal soap, repeat every 7–10 days for 3–4 cycles.
- Systemic imidacloprid drenches (per label, not on edible plants) work for severe cases.
- Isolate the plant from other plants for at least 4 weeks after the last visible mealybug.
How to prevent mealybugs
- Inspect new plants thoroughly, including the soil surface and root crown, before bringing them home.
- Avoid over-fertilizing — mealybugs prefer plants with high nitrogen levels.
- Wipe leaves down monthly so you spot early stages.
Per-species treatment guides
Treatment varies slightly by plant. Find your species below for a dedicated guide.
Source: UC IPM — Mealybugs