Question
My bonsai tree(coral bark maple) has lost all of its leaves and the tips of branches went black. Following a suggestion of an expert, I cut them off and increased the water dosage. Before that I re-potted the tree and found several worms. It has been two months since it first started blacking, and so far I noticed no visible change. I used the fertilizer once a week, the root system did not look damaged and I cut off only dead portions during the re-potting.

Please help me out here if you can.
Cheers

Answer
John:
Leaf drop and twig dieback are both symptoms of root and/or soil related stress.  This may be a water imbalance or even a bona fide root disease- something is interfering with proper root function.  Lots of things can bring on root stress.  Difficult to guess w/o seeing the plant and roots.  Careful watering to avoid excesses and removing the dead tips as you have will help.  Not sure what the worms are, but more than likely they may be a result of the problem rather than the cause.

If you have access to a reputable garden center in your hometown, you may consider carrying it to show them for their comments.

Regards
Steve