Plant care guide
Mealybugs on Snake Plant: Check the Leaf Bases
Updated
Why does my Snake plant have mealybugs?
White, cottony tufts tucked between snake plant leaves, low in the leaf bases or at the soil line, are mealybugs. NC State lists the longtailed mealybug as a common snake plant pest, and this species tends to hide in leaf whorls.
What to do first
Isolate the plant, spread the leaves apart and wipe each mealybug and egg mass off with a cotton swab dipped in rubbing alcohol, testing a small area first. Check the base and roots, and repeat every few days until no new tufts appear.
Snake plants rarely have pest problems, so white fluff between the leaves can be a shock. Penn State Extension says few pests bother this hardy plant, but that mealybugs and spider mites occasionally do. NC State Extension lists the longtailed mealybug among the common insect problems of Dracaena trifasciata.
Where they hide on a snake plant
The RHS describes mealybugs on sansevieria as sap-sucking insects that hide between the leaves. UW–Madison Extension adds that the longtailed mealybug frequently conceals itself in leaf whorls (UW–Madison: Mealybugs).
That makes the tight base of each fan of leaves the place to look. Check:
- Inside the leaf bases. Gently spread the leaves where they emerge from the mix.
- At the soil line. Washington State University Extension says mealybugs feed at the base of the plant and even below the soil (WSU: Mealybugs).
- Around the drainage holes. UW–Madison says small white cottony masses there suggest mealybugs on the roots.
- On the leaf below. Clemson Extension says mealybugs leave sticky honeydew that supports black sooty mould (HGIC 2252).
UC IPM describes the longtailed mealybug by its distinctive long tail filaments (UC IPM Pest Note 74174).
Rule out look-alikes
- Scale. University of Maryland Extension lists snake plant as a host of fern scale. Scale forms flat brown or white ridged bumps that do not move. See our snake plant scale guide.
- Thrips. Colorado State Extension describes thrips damage as silvery patches with tiny dark specks (CSU: Managing Houseplant Pests). See snake plant thrips.
- Spider mites. The RHS says these are usually only a problem in hot, dry conditions; look for stippling and fine webbing.
What to do
- Isolate the plant. UW–Madison says mealybugs crawl between plants whose leaves touch.
- Test alcohol on a small area. UC IPM advises a solution of 70% or less isopropyl alcohol, tested 1 to 2 days ahead for leaf burn.
- Swab every mealybug and egg mass. Clemson recommends a cotton swab dipped in rubbing alcohol for light infestations. Work down into each leaf base.
- Clear the crown. WSU says removing soil around the crown may be needed to reach mealybugs below the surface.
- Repeat. UW–Madison says washing and wiping rarely remove every pest, so check again every few days. Insecticidal soap or horticultural oil labelled for houseplants must reach the hidden spots to work, and several applications may be needed.
- Unpot if the plant keeps declining. UW–Madison says root mealybugs often can be confirmed only by removing the root ball, and are hard to control.
If the roots are infested
UW–Madison says replacing a plant is often the most practical answer to root mealybugs. Penn State notes that snake plant is most easily propagated by division. Separate a clean, healthy division, inspect it closely, and pot it into fresh mix and a clean pot.
Pets
The ASPCA lists snake plant as toxic to dogs and cats because of saponins, with nausea, vomiting and diarrhoea as signs. Keep trimmings and treated swabs out of reach.
Prevent a return
- Quarantine new plants. Clemson suggests six weeks apart, checking weekly.
- Look into the leaf bases each time you water.
- Keep pots apart so leaves of neighbouring plants do not touch.
Our mealybugs guide covers species and treatments across houseplants. For other snake plant problems, see snake plant yellow leaves or the snake plant hub.
References
- NC State Extension Gardener Plant Toolbox: Dracaena trifasciata
- RHS: Sansevieria growing guide
- UW–Madison Extension: Mealybugs
- Penn State Extension: Snake Plant, a Forgiving, Low-Maintenance Houseplant
- UC Statewide IPM Program: Pest Notes: Mealybugs (Publication 74174)
- Washington State University Extension: Mealybugs
- Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
- University of Maryland Extension: Scale Insects on Indoor Plants
- Colorado State University Extension: Managing Houseplant Pests
- ASPCA Animal Poison Control: Snake Plant
How this guide was put together: NC State Extension, the RHS, UW–Madison Extension, Penn State Extension, UC Statewide IPM Program, Washington State University Extension, Clemson Cooperative Extension, University of Maryland Extension, Colorado State University Extension and ASPCA guidance.