Oleander scale

The small whitish oleander scale can infest a variety glasshouse plants, including oleander, dracaena, palms and ornamental asparagus.

Oleander scale (<EM>Aspidiotus nerii</EM>) on Oleander (<EM>Nerium oleander</EM>)

Quick facts

Common name Oleander scale
Scientific name Aspidiotus nerii
Plants affected A variety of glasshouse plants
Main symptoms Whitish 2mm diameter scale insects on leaves and stems
Caused by Sap sucking scale insects 
Timing All year
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What is oleander scale?

Oleander scale is a sap sucking true bug that appears as a flat, oval, whitish-brown insects on leaves and stems of glasshouse plants. The whitish covering of the insect is waxy and repels liquids. The adults reach up to 2mm long, the immature stages (crawlers) are much smaller.

It does not produce honeydew and breeds throughout the year.

Symptoms/

Infestations of oleander scale are characterised by the encrustations of the 2mm diameter scales on leaves and stems of glasshouse plants. Common host plants include Acacia, Asparagus plumosus, azalea (Rhododendron), Cyclamen, Dracaena, Nerium oleander (oleander) and palms. Heavily infested plants can lack vigour. It can appear similar to other diaspid scale insects

Control

Non chemical

Oleander scale is difficult to control. Although scraping the insects off the leaves can help reduce infestations this is unlikely to give good control. It can be worth considering replacing heavily infested plants.

Chemical

Oleander scale can be difficult to control with sprays as the waxy covering gives them some protection and the best results are achieved by spraying against the newly hatched crawlers. Heavily infested plants may need several applications.

  • Contact sprays containing deltamethrin (e.g. Bayer Sprayday Greenfly Killer),  lambda-cyhalothrin (e.g. Westland Resolva Bug Killer) or cypermethrin (e.g. Py Bug Killer) can give control if applied thoroughly to the underside of leaves
  • The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is absorbed into the foliage and taken in by the young scales as they feed
  • Organic pesticides, based on plant oils or extracts (e.g. Vitax Organic Pest & Disease Control Concentrate) or fatty acids (e.g. Bayer Bug free, Doff Greenfly and Blackfly Killer) or based on pyrethrins (e.g. Bug Clear for Fruit & Veg, Defenders Bug Killer, ecofective Bug Killer (also contains fatty acids)) can be used. These are contact in action, have a short persistence and thorough application to the underside of leaves is required. More frequent applications of organic pesticides may be required to deal with the scale nymphs as they hatch
  • Note that dead scales can remain firmly attached to the plants. The success of any treatment can be gauged by the extent to which new growth remains free of infestation
  • Inclusion of a pesticide product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener
  • Do not spray on or near plants in flower due to the danger to pollinating insects

Downloads

Pesticides for gardeners  (Adobe Acrobat pdf document outlining pesticides available to gardeners)

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