The suggestion that your soil is not acid enough is probably wrong. I
have worked on this problem and the symptoms take several years to
develop and are not localized as your problem appears to be. It looks
like fire blight but i don't think pine is susceptible. There are some
white flecks in the last picture. Are these mushrooms? Possibly, you
have Fomes Annosum (there is a new classification for this fungus, but i
forget the new name). The holes you mention may be caused by small
rodents burrowing, transporting the spores of the fungus. Burrowing
animals may damage the roots allowing the fungus a point of entry.
However, a healthy tree is often able to repel such an attack. Are
there other potential sources of stress? Traffic by heavy equipment?
Digging near the roots of the trees? Other possibilities? What type of
pine are we talking about and what region are you in? More info would
\Not just another crazy bastard...I'm more than that!/