Posted: 27/09/2015 at 15:25
That is one severe infestation of scale insects. There are insecticides which will kill it. You need to get one which is based on Horticultural soft soap. The white covering is a waterproof wax which stops the insecticide from reaching the creature. The soap dissolves the wax and whammy!
It i9s not going to be a quick cure either.