hemispherical scale

Symptoms

Dome-shaped dark brown shiny scales (3-4mm) on stems + leaf veins, sticky honeydew + sooty mould, gradual plant decline + leaf drop, scales appear in clusters along stems + leaf midribs.

Plants affected

• rubber plant
• dwarf umbrella tree

Easily confused with

• brown soft scale

  How to tell them apart: Coccus hesperidum (brown soft scale) appears as flat, low, oval, soft-bodied bumps that lie almost pressed against the leaf or stem, often pale yellowish-brown to olive and frequently mottled with darker patches; they cluster along the midrib and veins on leaf undersides and produce abundant sticky honeydew. Saissetia coffeae (hemispherical scale) is clearly raised into a smooth, shiny, dome- or helmet-shaped hemisphere, uniformly chestnut to dark brown with no mottling, and the older shells feel hard and convex like a tiny half-pea. The key visible test is profile: run a fingernail across them — brown soft scale is flat and yielding, hemispherical scale is a hard rounded dome standing well off the surface.

Common questions

How do I recognise hemispherical scale on rubber plant?

Dome-shaped dark brown shiny scales (3-4mm) on stems + leaf veins, sticky honeydew + sooty mould, gradual plant decline + leaf drop, scales appear in clusters along stems + leaf midribs.

Do I have to report hemispherical scale?

No. hemispherical scale is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is hemispherical scale treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.