That looks like Cottony Camellia Scale.
Scale are a type of sucking insect that doesn't look much like we normally think of as insects. They stay still and settled for most of their lives. The white fluffy part covers eggs that the mother laid before she died and dropped off. 
Here is our page on them: 
https://extension.umd.edu/resource/cottony-camellia-scale/

The page gives you some control options, but if you are willing, I had good luck flipping leaves (they're on the underside) and squishing them or wiping them off.


Christine

Thanks so much.  It is severely infested.  I cut off the worst branches but, based on the fact sheet, I think I have to remove the bush.  Sigh.

In the meantime, I sprayed with horticultural oil.

 

Cindy  (lapsed HoCo Master Gardner) 

Hello Cindy,

Scale is treatable and you don't need to remove the shrub. You can physically remove the scale by hand (pruning extensively isn't recommended since that will stress the plant), or spray it with a low-toxicity insecticide (like the horticultural oil you started using) around the time the crawlers for this species are expected to be out (as indicated in the page linked previously). After a period of time repeating treatments as necessary, the scale population should be under control.

Miri