As some people mentioned, it is a good idea to ID them first, and depending on the species, if they are parasitic, they can kill the tree or leave it weak enough to die from something else
Some species, even if you cut their visible stems, but leave the host trunk intact without treatment, they can regrow from embedded haustoria (specialized roots) that penetrate deep into the host’s vascular system, allowing them to regenerate from internal tissues.










Let us know how it goes. I love seen how these cases unfolds in the fediverse