Q.Holly bush diseased
My holly bush is COVERED with white ‘tubes,’ dense and side by side. When I trimmed the bush, I saw that underneath the leaves were deep brown/black also. Should I take it down? The damage is extensive.

Oh thank you so very much! I searched the web trying to find what it could be and you got it right away. Now I'll research neem oil.
Have a great day & really thank you!
Rose

This seems to be a severe case of Camellia Scale.
You can treat it with Neem Oil.
https://www.gardeningknowhow.com/ornamental/shrubs/holly/diseases-of-holly-bushes-pests-and-diseases-damaging-holly-bushes.htm
https://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-problems-holly-leaf-spot-or-holly-tar-spot.htm
https://www.gardeningknowhow.com/ornamental/flowers/camellia/identifying-and-fixing-problems-with-camellias.htm