Oak tree with black stuff coming out of trunk
Tonight I noticed that one of the big old oak trees in my backyard has something ugly going on. It's developed a slit in the base of the trunk. Inside the slit is some kind of moist goo. There are small flying insects about the size of gnats alighting on the damaged section and to either side of the damaged section, and I can't tell for sure but there look to be some kind of grubs or larvae in the damaged section too. Here are some photos I just snapped:
My question is whether this is a tree emergency that I need to get an arborist out here to attend to or whether this is something I can treat on my own. Any advice would be greatly appreciated.
Here is a link that might be useful: oak damage photos