[cleversquirrel]

  Hi all
    My pear tree is dying and have notices a hole in the trunk about quarter of an inch in diameter,very deep and goes up inside the tree a long way and there appears to be wood or dropping pilling up at its base.Any body got any ideas and has the tree had it?

All the best Squirrel

[Trillium]

What's the approximate age of the tree? This is sometimes a determining factor.
The boring could be some type of borer and you'd have to get a systemic pesticide to kill these. Some people say you can simply stuff some mineral oil up the holes to smother the borers but it really doesn't work as the holes can be quite long and your stick isn't.

[cleversquirrel]

Hi
 
   The tree is in a pot and isnt that old by tree standards but the leaves have turned black and any fruit that my have been there has dried and fallen off with some of the leaves.

Squirrel

[oldbean]

If you try a twig and it snaps, the tree is no more.

[SG6]

Had similar on an apple tree some years back. Small hole that extended about 2 - 2.5 inches into and up the trunk. I squirted a pesticide in it. The tree seemed OK after that although it didn't seem to cause it any harm before I did it. 

Basically all you can do is try and bump off whatever is in there and then hope that the tree recovers.