It would be good to have some more information.  Can you send some additional photos of the entire tree that are affected.  it is good practice to first identify what is the cause of the problem, if it is caused by an insect, what stage it is in prior to applying an insecticide.  That way we are not applying a product that may be unnecessary or applied at an incorrect timing.   

The white pine sap in the photo is tall (30 feet??) and has significant sap flow, but only one area of browning near the top. One photo shows the brown needles and the third shows the sap flow.

I have more photos if you need them.

It is difficult to determine the cause from the pictures and information provided.  Generally borer insects do not cause the tree to die, but can attack trees that are already under stress from some other event.  The sap you see flowing from trees may not be of great concern.  I wouldn't necessarily think you need to applying an insecticide unless you can find more active insects/damage on trees. You may consider contacting an arborist (https://www.treesaregood.org/findanarborist/arboristsearch) and have them come to your site and do a more detailed examination.