Scales are small, stationary brown greenish insects occasionally found sucking sap from avocado leaves. Soft scales such as Coccus spp. excrete large amount of honeydew, which lead to the development of sooty mould on leaves, branches and fruit. Honeydew attracts ants, which while feeding on the honeydew protect scales from natural enemies.
Armoured scales such as the coconut scale (Aspidiotus destructor) may encrust young twigs, leaves and fruit. They do not produce honeydew. Scales are usually not a problem in avocado orchards; however, damage can be serious on young tress and small twigs may be killed. Although the presence of scales on the skin of fruit does not cause internal damage, it may lead to rejection of fruit, especially if grown for export.
- Conserve natural enemies. Scales are usually kept under control by parasitic wasps, ladybird beetles and lacewings, provided no broad-spectrum pesticides are used and no ants are present.