Wesley Rush

My dad accidentally exposed this unknown hive earlier when he started to cut down a dead oak in our back yard, will these bees be able to make it through the winter with that big of an opening in it? The hole is about 10" in diameter and the comb is about 16" from the end of the opening.

I'm hopeful that it is still usable, as there is already fungal growth happening on parts of it.

I have recently come into tons of wood from a 75' sycamore tree that was killed about a year ago when my dad accidentally over flowed his pasture spray tank filled with 2-4D near the base of the tree. I assume that there is some residual chemical in the wood, but is this wood safe to use in hugelkultur beds? I've never built any but I hate to see such a good resource piled up and burned, which is the alternative.