Scale on houseplants
Indoors the first sign is almost always the honeydew — a sticky leaf or windowsill, or black sooty mould on the leaves below — rather than the insects. Brown soft scale breeds all year inside, so crawlers keep appearing. The scale destroyer beetle eats the eggs and young of soft scale, and sticky leaves hinder it, so rinse the plant before releasing. On a small plant, scraping off the adults is quicker.
At a glance
- Damage
- Flat brown bumps on stems and veins; heavy honeydew
- Type
- Sap feeding
- Settings
- Indoors, Under glass, Garden
- Threshold
- Sticky leaves plus live scale on a stem or midrib
- Release
- Rhyzobius lophanthae
- Rate
- 2–5 beetles per infested plant, every 1–2 weeks
How to confirm it
Flip a bump over with a fingernail. A soft scale comes away whole, cover and body together; an armoured scale leaves its body behind on the plant. Squash one: a live scale exudes fluid, while a dead or parasitised one is dry and may have a round exit hole.
Identification, lifecycle, degree days and every control option are on the full Brown soft scale profile. Not sure it is this pest? Answer four questions about the damage.
Work it out
How many do I need?
Carries Rhyzobius lophanthae and houseplants through so nothing is re-entered. Open the calculator →