British Columbia: What's wrong with this 30 year old Camellia?

Hello, this camellia in Courtenay BC is at least 30 years old, but may be older. Lately (as in the last couple years) it's been showing some strange patterns on the leaves. There hasn't been any major changes in it's light or water conditions. What could be going on with it and how can we help it?

Thanks!

 

Have you checked the undersides of the leaves? Cottony Camellia Scale can cause similar damage but is often unnoticed from the top (from personal experience). It also often causes sooty mold on the lower leaves.

 

Otherwise maybe the hot weather of recent years. And/or the dryness associated with climate change.

 

My thoughts too. Camellia doesn't like droughty conditions.

 

Thank you everyone, I think the suggestion of scale might be right - does this look like cottony scale? I've looked it up and it looks like there is a bunch of other types of scale too.

The internet seems to indicate we should treat by pruning back affected branches and generally thinning the interior, then treating with either or both oil spray or pesticide spray, and that we should be doing it about now to try to target crawlers.

Does that seem about right? I must admit I'm pretty intimidated - this thing is about 12 ft + tall and 8 ft wide. Trying to treat all the branches will be very difficult but it's very dear to us and we want to keep it in good shape.