Spider Mites on Fiddle Leaf Fig: Spot, Wash and Treat

Fine speckles across a fiddle leaf fig’s big leaves are easy to dismiss as dust, until the leaves start to fade. NC State Extension says the fiddle leaf fig has no serious pests, but advises houseplant owners to monitor for scale, aphids, mealybugs, thrips and spider mites. The RHS also lists red spider mites among pests of ornamental figs.

Confirm it is spider mites

Clemson Extension describes light speckling on the upper leaf surface and an overall faded look (HGIC 2252). Colorado State Extension says injury often starts as patches of white flecks on the underside near the base of the veins (CSU: Managing Houseplant Pests). It names figs among the common hosts.

Check:

• The undersides. Iowa State Extension says mites live mainly on the undersides of leaves (Iowa State: Insect Pests).
• The paper tap. Tap a leaf over white paper and watch for specks that move.
• Webbing on leaves and stems, which Iowa State says appears once populations are large.
• The spot. UC IPM says plants under water stress are highly susceptible, and mites favour hot, dusty conditions (UC IPM Pest Note 7405).

NC State notes that fiddle leaf fig leaves are bullate and not glossy, and can be up to 46 cm (18 in) long. Check each leaf, top and underside, rather than sampling a few.

Rule out look-alikes

NC State lists other causes of leaf damage on this plant:

• Leaf scorch from too much direct sun. Check whether the damage is on the sun-facing leaves only, with no mites on the paper test.
• Brown spots from temperature swings near heating or cooling vents; see fiddle leaf fig brown spots.
• Leaf drop from too much or too little water; see fiddle leaf fig dropping leaves.

Cottony tufts in leaf joints are mealybugs instead; see fiddle leaf fig mealybugs.

What to do

1. Isolate the plant. Colorado State says mites crawl or are carried to nearby plants.
2. Wash both sides of every leaf. Colorado State says repeated washing with a jet of water over several weeks should reduce mites to low levels. A tall fig may be easier to wipe with a damp cloth, supporting each leaf from below.
3. Repeat weekly. Clemson says weekly sprays for several weeks are often needed.
4. Spray oil if needed. Colorado State rates horticultural oils as probably the most effective spray. UC IPM lists insecticidal soap or oil, and warns that some broad-spectrum insecticides often trigger mite outbreaks. Test on one leaf first.
5. Prune badly damaged leaves. Bag them and remove them from the room.

Fix the conditions

• Keep it away from heaters and hot glass. NC State advises protection from afternoon sun and a temperature above 13 °C (55 °F).
• Water evenly. NC State says the plant is sensitive to overwatering; UC IPM links drought stress to mites.
• Raise humidity. NC State says it performs best in medium humidity, and Colorado State lists increased humidity among the most effective mite controls.

Safety

NC State says the milky sap can irritate skin and recommends gloves when pruning. It also notes ingestion can cause oral irritation, drooling and vomiting. The ASPCA lists Ficus species in its weeping fig entry as toxic to dogs, cats and horses.

Prevent a return

• Wipe the leaves regularly. Clemson says washing smooth-leaved plants every two to three weeks discourages pests.
• Check undersides weekly in winter.
• Quarantine new plants for six weeks, as Clemson suggests.

Our spider mites guide covers mite biology and treatment options in more depth. More care pages are on the fiddle leaf fig hub.

References

• NC State Extension Gardener Plant Toolbox: Ficus lyrata
• RHS: Ornamental figs growing guide
• Colorado State University Extension: Managing Houseplant Pests
• UC Statewide IPM Program: Pest Notes: Spider Mites (Publication 7405)
• Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
• Iowa State University Extension and Outreach: Diagnosing Houseplant Problems Caused by Insect Pests
• ASPCA Animal Poison Control: Weeping Fig (Ficus sp.)