Mealybugs on houseplants: how to identify and treat them

Mealybugs — the pest hiding in plain cotton

Mealybugs are one of the most common and frustrating houseplant pests. They're small, slow-moving insects that protect themselves with a white, waxy, cotton-like coating, and they feed by sucking sap from the plant's tissue — which weakens the plant over time and slows its growth.

What to look out for

White tufts — Small white fuzzy spots that look like bits of cotton or lint. Mealybugs often hide in the "crooks" of the plant — where the leaf meets the stem, under leaves, or tucked inside new growth. They can also hide under the rim of the nursery pot or in the top layer of soil.
Sticky residue (honeydew) — As they feed, mealybugs excrete a sticky substance called honeydew. If your leaves feel tacky or look shiny, check the undersides of the leaves and stems for pests.
Sooty mold — In more advanced infestations, a black, soot-like fungus may grow on the sticky honeydew the insects leave behind.

Examples of mealybugs in real homes

Mealybugs clustered in the crooks of a Yucca — White tufts gathered in the leaf crooks

White cotton-like mealybug clusters on a stem — The cotton-like clusters up close

Mealybug infestation spreading along palm fronds — An infestation spreading along the fronds

Mealybugs hiding where the leaf meets the stem — Hiding where the leaf meets the stem

Advanced mealybug infestation on a houseplant — A more advanced infestation

Why they’re difficult to eliminate

Mealybugs are protected by a waxy outer coating that repels many water-based sprays. Because of this "armour", treatments have to be targeted and repeated consistently to fully eliminate them.

How to treat them

Isolate immediately — Move the affected plant to a separate room to stop the infestation spreading to other plants.
Rinse the plant — Take it to the sink or shower and use a steady stream of water to wash away as many pests as possible. Wipe the pot down too — with alcohol or soapy water — to remove any hidden pests.
Prune heavily infested areas — Remove heavily infested leaves or stems with clean scissors and dispose of them immediately.
Use an insecticide — Apply an insecticide thoroughly across the entire plant, including the stems and the undersides of leaves. Repeat weekly for about 5 weeks to break the pest life cycle.
Target with alcohol — Dip a cotton swab in rubbing alcohol (isopropyl alcohol) and dab it directly onto the white tufts. The alcohol dissolves their waxy coating and kills them on contact.