Description
Scales are sap-sucking insects with protective coverings. There are about 400 species of scales in New Zealand, and some are specific to their host plant.
Scales fit into 2 main groups, soft scales and hard (armoured) scales. They can vary in appearance between species. Some species are very small, growing between 1 and 2 millimetres in size, are immobile and live under protective wax covers. Other species are larger and grow between 5 and 10 millimetres in size, are mobile and can produce eggs in large ovisacs (egg containing capsules). Scales vary in colour but are normally black, brown, grey, white, or translucent.
Common native plant hosts
Broad range of native plant hosts.
Symptoms and damage
- Leaf yellowing and defoliation.
- May attract growth of fungi such as sooty mould.
- Plant stress.
- Wilting.
- Scales can transmit diseases to plants.
- Unsightly.
Prevention and control tips
- Chemical insecticides.
- Neem.
- Organic pyrethrum.
- Plant soap.
- Spray oil.