I think someone asked and was answered about this very thing in another post. I believe the answer was "pine pitch gall" or something along that line.

All the pines in my yard and in the yards of my neighbors seem to have this (we grow a lot of these and also the Monterey pine here.) I think it is just a matter of removing the dying parts until the entire tree (and this especially true of the Monterey) needs to be taken before it kills someone with a dropped branch or worse.