What are Scale insects?

What are Scale insects?

Scale insects are major pests on ornamental trees, orchards, indoor plants, and ferns.

Some common species are:

• pink wax scale
• black scale
• soft brown scale
• citrus red scale

What do scale insect affect?

Scale insects suck the sap from leaves, stalks, and stems, resulting in stunted plant growth, defoliation and even plant death. They produce honeydew that encourages sooty mould growth.

How to identify scale insects

Scale insects range from 1-5mm in size and can be either soft or armoured. Adult female scales remain permanently attached to the host plant, without moving.

All adult scale insects secrete a waxy protective coating which makes it difficult to get rid of them. They are more susceptible to treatment during their juvenile phase without this coating.

What are the symptoms of scale invasion?

Symptoms of scale invasion include:

• bumps on the underside of leaves
• presence of honeydew and sooty mould
• distorted or stunted fruit
• dieback of twigs and branches
• yellow spots on leaves and defoliation

How to control scales

Methods of control for minor infestation include using a damp cloth to rub off scale insects, spray the infested plant with Eco-oil or Neem oil.

Encourage natural predators like scale-eating ladybird, lacewings, and parasitic wasps by growing beneficial attracting plants such as coriander, fennel and dill, thyme, Queen Anne’s lace, and alyssum.

Dispose of heavily infested plants (bag & bin) and replace them.

Top tip for scale insects

Keep ants away as they protect the scales from their natural enemies.