Answer: Pine trees sometimes develop fissures in the bark and sap can run down the trunk or branches. It doesn't necessarily mean that anything is wrong with the tree - it's a natural thing. However, if the tree has been injured (weed trimmers, lawn mowers, etc.) the sap indicates the tree is trying to seal off the wound. Again, if the tree is otherwise healthy, it should be able to compartmentalize this injury with compromising its health. Small sections of bark can fall off all on their own - again it's a natural thing.
On the other hand, if you can see bore holes, your pine may indeed be playing host to bark beetles. They are extremely difficult to control. You might want to check with your local cooperative extension office for locally acceptable controls. I'd hate to suggest you remove a 30' tree without getting another opinion!
Best wishes with your pine~
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