Thank you all for your input. I had an arborist out to the property to examine the tree/s. In addition to the 4 pines are two apple, and 8 maples of various types. We spent about an hour examining the trees, and he explained what the various leaf/needle conditions, holes and disturbances in the bark, root structures and other indications meant. Approx. half the trees are in good shape and just need some thinning and shaping. The others have parasites and/or beetle issues.
After his examination, including digging into the sap blobs on the bark, he felt confident that with treatment he would be able to save most if not all of them. In protective gear, he mixed and applied a systemic liquid in a ring around the tree, then soaked it into the ground. Afterwards, using a portable pressure washer with a soft spray nozzle, misted each tree. He stated this was his way of 'tricking' the tree into encouraging the root structure to take in more water and the medicine.
He seemed quite knowledgeable and confident he could save them. Hoping he is correct!
Thanks again,
John