I have large black oak growing out of a shale cliff about 5' above a lake in
western NY.

Every year it develops holes that liquid flows out of. Occasionally there
are piles of sawdust below the holes. The holes are about 3/4" diameter.
There are healed holes elsewhere on the trunk.

I have found what appears to be the remains of large moths stuck in two of
the holes, but don't know if they are related to the problem or when in
after the sap.

Any idea what the problem is, or what I should do about it? Is there a
better group to post a tree question to?
Thanks.