djken

Hi all, Brand new here without much tree knowledge. Recently bought a house with a sycamore in the garden. This morning I've found a few chunks of bark have fallen out of part of the trunk, and this whole section is riddled with small holes. The wood under the surface is very degraded and comes apart like sawdust, and seems to have a few larvae and something like dense cobweb strewn about it. Any suggestions on what this is and if it can be treated would be much appreciated!