Mealy bugs are small white and look harmless. Unfortunately they are not. The secondary problems caused by the sticky exudation are what cause plants to suffer. If you have them in large numbers, you need to treat the problem, otherwise they'll be back, sucking sap from the plants. For small numbers, spray with water and wipe off. Once the second stage, sooty mould, appears, the time has come to take stronger measures. Some plants can become very weakened, then not able to survive harsh conditions like our hot dry summers.
1. Make-your-own treatment: Spraying with diluted methylated spirits. Mix 1 part methylated spirits to 2 parts water. If mixed too strong, leaf burn can result. Soap flakes or even dish-washing liquid can also be added.
2. Treatment using oil sprays: Eco Oil or Neem Oil are fantastic producst that controls the infestation by smothering the insects. The oil also works as a protective covering on the plant to reduce the chances of re-infestation.