Schefflera Pests: Spider Mites, Mealybugs and Scale

Pests on a schefflera are common, treatable, and easier to deal with early. Clemson Extension’s schefflera factsheet names mealybugs, scale insects and mites as the common pests of scheffleras. The RHS lists the same three for the dwarf umbrella tree: glasshouse red spider mite, mealybugs and scale insects.

Spider mites deserve the most attention. UF/IFAS says umbrella trees grown indoors are susceptible to infestations of spider mites.

Identify the pest first

Treatment depends on the pest, so look closely before you spray. Clemson’s houseplant pests factsheet suggests a 10X hand lens, and says pests are most often on the undersides of leaves.

Clue	Pest	What Clemson describes
Pale speckling on upper leaf surfaces, faded look, fine silk webbing	Spider mites	Too small to see easily; damage is usually the first sign. Leaves bronze or yellow if unchecked
White, cottony tufts in leaf joints and under leaflets	Mealybugs	Pale, slow-moving insects 3–6 mm (⅛–¼ in) long, covered in white wax
Flat or domed bumps on stems and leaf undersides that do not move	Scale	Immobile adults 1.5–13 mm (1/16–½ in) across, with no visible legs
Sticky, shiny leaves; black film on leaves below	Honeydew and sooty mold	From mealybugs or soft scale feeding above

UF/IFAS lists scale and sooty mold as a minor problem on schefflera. The black film is a fungus growing on honeydew, so it clears once the insects producing it are gone.

Spider mites

Clemson says spider mites suck plant sap, causing light speckling and an overall faded look. Heavier infestations show silky webbing. They are most troublesome on plants kept indoors all year.

1. Take the plant to a shower or outdoors in mild weather. Spray it forcefully with water, including leaf undersides, to dislodge mites and break up webs. Clemson says repeated water sprays help control them.
2. Skip insecticidal soap: Clemson names schefflera among the houseplants that soap can injure. If water sprays are not enough, use a horticultural oil labeled for houseplants, tested on a few leaflets first.
3. Repeat. Clemson says it is often necessary to spray once a week for several weeks.

For a closer look at mite damage, see our spider mite guide. If you are choosing a cultivar, Clemson notes that the umbrella tree ‘Amate’ has resistance to spider mites and Alternaria leaf spot.

Mealybugs

Clemson says mealybugs cluster on lower leaf surfaces and in leaf axils, where the leaf meets the stem. Their wax repels sprays, which makes them harder to control.

1. Wipe each mealybug with a cotton swab dipped in rubbing alcohol.
2. Check the axils and the crowded growing tips of a dwarf schefflera, where they hide.
3. Repeat the alcohol swabs weekly; do not use insecticidal soap on schefflera (see below). Clemson says a heavy infestation may mean discarding the plant.

Scale

Clemson says early scale infestations can be scraped off with a fingernail. Adults are protected by their waxy covering, and the mobile young, called crawlers, are the stage sprays reach. Scrape off what you can and check again weekly. Our schefflera scale guide covers follow-up treatment without soap.

Spraying safely indoors

Clemson’s general advice for houseplants is to try handpicking, water sprays and insecticidal soap first, but its notes on insecticidal soap name schefflera as a plant soap should not be applied to. On schefflera, stick to handpicking, water sprays and alcohol swabs, then a tested horticultural oil. If you use any product, check that the label covers indoor houseplants. Clemson says pesticide injury often shows within 5 to 10 days, as distorted, yellowed or burned leaves. Our comparison of neem oil and insecticidal soap covers the two most common options.

Wear gloves when handling or pruning heavily infested stems. NC State Extension says schefflera sap can irritate sensitive skin. If you need to know which schefflera you have, see how to identify a schefflera.

Keep them from coming back

• Isolate new plants. Clemson suggests six weeks apart from other houseplants, checking weekly.
• Inspect before bringing a plant indoors after summer outside, including the outside of the root ball.
• Wash the leaves. Clemson says washing smooth-leaved plants every two to three weeks discourages pests.
• Keep the plant growing well. Clemson notes stressed plants are more prone to pests. Scheffleras prefer medium to bright light and day temperatures of 18–24 °C (65–75 °F), Clemson says.

References

• Clemson Cooperative Extension HGIC 1511: Schefflera
• Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
• UF/IFAS Extension ENH743/ST585: Schefflera actinophylla, Schefflera
• RHS: Schefflera arboricola
• NC State Extension Gardener Plant Toolbox: Heptapleurum arboricola
• Colorado State University Extension: Managing Houseplant Pests