Plant care guide
Scale on Ficus: What the Bugs Look Like and How to Clear Them
Updated
Why does my Ficus have scale?
Scale on a ficus looks like small tan to brown bumps lined up along leaf veins, on the leaf stalks and on young twigs, often with sticky leaves or a sticky floor below. Some are oval soft scales; others are flat, oyster-shell scales with tiny white males. They do not move and flake off under a fingernail.
What to do first
Isolate the ficus without moving it far, scrape off every scale you can find, then treat the crawlers with a horticultural oil labelled for indoor plants. Keep treating through a full generation, which Colorado State Extension puts at two to four months.
Sticky leaves and a tacky floor under a weeping fig are often the first clue, long before you notice the insects. Scale is a common ficus problem. Colorado State Extension says soft scale problems are most frequent on ficus, citrus, ferns and ivies (CSU: Managing Houseplant Pests). NC State Extension advises watching for scale on Ficus benjamina.
What scale looks like on a ficus
University of Maryland Extension lists Ficus as a host of the two scales below (UMD: Scale Insects on Indoor Plants).
| Brown soft scale | Fern scale (an armored scale) | |
|---|---|---|
| Adult females | Oval, light tan, yellow-green or yellow-brown with darker mottling, up to 4.75 mm (3/16 in) | Pear- or oyster-shell-shaped, flat, light to dark brown, up to 4.75 mm (3/16 in) |
| Other stages | Yellow crawlers | Smaller, elongate white males with ridges; yellow crawlers with red eyes |
| Where | Along leaf veins, on leaf undersides and stalks, young stems | Mostly on foliage |
| Honeydew | Yes, often heavy | No |
UMD says large numbers of fern scale males create white flecking or a snowy look on leaves. UC IPM explains the difference: armored scale covers lift off the body, while a soft scale’s cover is its body (UC IPM Pest Note 7408).
Other signs
- Stickiness. UMD calls honeydew the main sign of soft scale. It turns black with sooty mould.
- Yellow spotting on leaves, which UMD links to fern scale.
- Leaf drop and dieback. UMD lists both for heavy, prolonged infestations.
Scale is not the only reason a weeping fig drops leaves. The RHS says weeping figs shed leaves if conditions are wrong or they are moved (RHS: Ornamental figs). See our ficus dropping leaves guide.
Why treatment takes months
Clemson Extension says adult scales are protected by their waxy cover, while the mobile crawlers are vulnerable (HGIC 2252). Colorado State says insecticides must keep covering a whole generation, two to four months, to stop reinfestation. UMD gives about 60 days per generation for brown soft scale and about 95 days for fern scale, with overlapping generations year-round indoors.
What to do
- Isolate without a long move. UMD advises quarantining plants with scale. Because the RHS says weeping figs dislike being moved, shift it only as far as you must.
- Scrape off what you can. UMD says scale should flake off with a fingernail, toothpick, cotton swab or soft toothbrush. Colorado State says scales killed this way can stay attached and look alive.
- Prune heavily infested twigs and bag them.
- Treat the crawlers. Colorado State rates spray oils as the most effective treatment for scale, and the most effective for armored scales. UMD lists horticultural oil, insecticidal soap, or a systemic product labelled for indoor plants, which works on brown soft scale only.
- Repeat and monitor. The RHS says dead scales can stay firmly attached, so judge success by new growth staying free of scale (RHS: Indoor plants, sap-feeding insects).
UMD adds that heavily infested plants are best discarded.
Safety
The ASPCA lists fig (Ficus benjamina) as toxic to dogs, cats and horses, causing gastrointestinal and skin irritation. Wear gloves when scraping and pruning, and keep pets away from wet sprays.
Prevent a return
- Inspect new plants. UMD says brown soft scale can arrive on plant shipments from any location.
- Quarantine arrivals for six weeks, as Clemson suggests.
- Check for stickiness on leaves and the floor every week.
Our scale insects guide compares scale types and treatments across houseplants. For more ficus care, visit the ficus hub.
Related guides
Other ficus problems we cover: repotting.
References
- University of Maryland Extension: Scale Insects on Indoor Plants
- Colorado State University Extension: Managing Houseplant Pests
- NC State Extension Gardener Plant Toolbox: Ficus benjamina
- RHS: Ornamental figs growing guide
- RHS: Indoor plants, sap-feeding insects
- Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
- UC Statewide IPM Program: Pest Notes: Scales (Publication 7408)
- ASPCA Animal Poison Control: Fig (Ficus benjamina)
How this guide was put together: University of Maryland Extension, Colorado State University Extension, NC State Extension, the RHS, Clemson Cooperative Extension, UC Statewide IPM Program and ASPCA guidance.