Deterioratiing Trunk close up

Its OK, one of mine is like this, :)

It's like an insect has had a field day on the trunk because it's on the other sides to, any ideas what does cause this and does it not weaken the trunk because it in real life does look lob sided, it was not like this when i brought it....??

all i know is the trunk is also the root system Bally, maybe its been damaged by something falling onto it, give it a good soaking before you wrap it up for winter..