Good day, There is an old oak, at least 107 years old, on my mother's property. It has always appeared healthy. A month ago, we noticed that something, perhaps a bee, had made a line of holes horizontally across the tree which leaks sap terribly. My mother, on the advice of a garden store, sprayed WD-40 on the holes, with no effect. In fact, there is now a new hole. The sap drains quickly and even seems to be squirting out at times. The holes are approximately 1/4 to 1/2 inch in diameter. Please advise on how to protect this old member of the family.

Greetings Julia,

Well, it sounds like your oak tree is the unwelcome visitor of a yellow-bellied sapsucker (a woodpecker). Despite the beauty of this migratory bird species, their damaged inflicted on yard trees is usually unwelcome. They are most common during the migratory season: spring and fall, though they can be found on your property outside the migratory season.

Now, I'm not sure why the garden store told your mother to spray WD-40 - bad idea!

To control sapsucker damage, you may wish to wrap the affected area of the tree with burlap (remove wrap during summer months). I've also heard of placing an artificial bird of prey, like an owl or hawk, on a branch near the affected tree to scare off the yellow-bellied sapsucker. Causing injury to the bird directly is a violation of state and federal law unless you receive a control permit by your state wildlife agency.

http://web.extension.uiuc.edu/regions/lawnandgarden/SapsuckerDamage.pdf

Best of luck!