Question
This tree was planted approx. 1 year ago.  Only recently I noticed quite a bit of sap draining from the trunk.  Someone said it maybe a bug?  I don't want to lose the tree, and will call an arborist if necessary.  Any suggestions as to what it may be and how to treat?

Answer
It does not sounds like an insect but possibly a disease called slim flux.

The foul-smelling and unsightly seepage of sap from the trunk of shade trees is commonly called slime flux or wet wood.  

Slime flux is a bacterial disease. The infected wood is frequently discolored or appears water soaked (wet wood). Gas (carbon dioxide) is produced by fermentation by bacteria. The gas produces pressure in the wood. This pressure forces sap from the trunk through cracks in branch crotch unions, pruning wounds, lawn mower wounds, other injuries and occasionally unwounded bark. This oozing of sap is termed fluxing. The flux is colorless to tan at first but darkens up exposure to the air. As fluxing continues, large areas of the bark become soaked. Many different microorganisms grow in the flux producing a foul or alcoholic smell. Various types of insects are attracted to the slime flux. If the fluxing continues for months, leaves on affected branches may be stunted and chlorotic. Grass may be killed where the flux runs down the trunk onto the grass.

Large mature landscape oaks have had problems with slime flux on the trunk or large exposed flare roots just above the soil line with no apparent wounds or injuries. Sap may continue to ooze for several weeks or months, but usually it eventually stops with no treatment and no apparent damage to the tree. This slime flux may be triggered by heat, drought and other stress.

There is no curative or preventive measures for slime flux except to maintain trees in a general good state of vigor and minimize wounds and injuries.

If there is loose or dead bark in the slime flux area, remove all of the loose bark and allow the area to dry. The best thing to do is to wash off the trunk to discourage bugs. Mix a pint of chlorine bleach in a gallon of water to make a final rinse. The flow of sap is periodic; it may disappear and not reoccur or you may see it every year.

Do not apply a wound dressing.

May want to try calling the local office of the State Forestry agency OR the Agriculture extension service and ask one of their specialist to take a look before you hire someone. IF you do hire an Arborist make sure they are certified. There are Tree service folks that are just tree removers that do not have the training to ID or treat a problem. Here is a web link to the organization that certifies Arborist. http://www.isa-arbor.com/findArborist/findarborist.aspx