We have a shrub that has undergone significant leaf loss and now the branches are starting to give way. With an upclose view there are millions of white things all over it. They don't look like they're moving, and when touched it smears.. are these pest droppings?

Here are a few pics. What is causing this and what is the treatment. Is it too late? It doesn't look to have spread to our normal bushes yet.

Pic 1
Pic 2
Pic 3