Scale Insects

Scale are tiny sap sucking insects with protective coverings that can be found attached to plant leaves and stems.

Identify the problem Identify the problem

Scale are sap sucking insects that have protective coverings. The protective coverings can be hard and waxy to soft and foam-like. The shield like protective cover or frothy covering can make it difficult to identify them as insects. Scales are commonly brown, black, grey or white. See the gallery for some examples.

Scale insects fix themselves to leaves and stems and suck sap. Their waste products are a sweet honeydew that ants and wasps will feed on readily. The sticky honeydew will also encourage moulds such as sooty mould. It may be difficult to see the scale if they are covered by the mould. Infested leaves usually turn yellow. Some scale live beneath bark and are not easily seen.


 To Get Rid of Scale Insects:

  • Scale insects can be difficult to get rid of but spraying with PLANThealth Spectrum and/or Organic Insect Control followed by Organic Super Spraying Oil is most effective, killing scale through suffocation. However, do not spray in the middle of the day or in strong sunlight or high temperature as this can cause burning of the plant. It is best to apply to the crawling and young stages of scale insect.
  • Once control has been achieved PLANThealth Spectrum is a good option for prevention and control of scale and the mould that often accompanies them. They can also be applied before (at least one day) application of Organic Super Spraying Oil.


Control Ants and the Sap Sucking Insects they 'Farm' in Trees, Shrubs and Ornamantals

  • Apply LawnPro Protect on the the soil around the roots of affected plants. This kills and prevents ants moving up the plants, and is systemic and taken up by the roots of the plant to control the sap sucking scale and other insects directly.

Did You Know Did You Know

There are many species of scale insect in the family Coccoidea. In New Zealand common pest species include:

  • San Jose Scale - Quadraspidiotus pemiciosus
  • Rose scale - Aulacaspis rosae
  • Oystershell scale - Quadraspidiotus ostreaeformis
  • Soft brown scale - Coccus hesperidum
  • Apple mussel scale - Lepidosaphes ulmi
  • Greedy scale - Hemiberlesia rapax
  • Cottony cushion scale - Icerya purchasi
  • Juniper scale - Carulaspis juniperi
  • Brown scale -  Parthenolecanium corni


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Organic Super Spraying Oil

Organic Super Spraying Oil

Horticultural oil protects your plants from a range of insect pests, mites and diseases.

Plant Health Spectrum

Plant Health Spectrum

Insect pest and disease control for roses and ornamentals.


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