Unknown fungus on an olive tree.

Dgwhitmoresounddesign

Can anyone help me identify what this is and what the best way to to deal with it? 

I’m pretty new to all this so any help will be much appreciated. 

Thanks

Dovefromabove

I think that’s Woolly Aphids

Lots of info here https://www.rhs.org.uk/advice/profile?pid=724

Hope that helps 😊