We have a 30 year old white pine that recently started browning and dropping needles on just one side. The affected limbs are riddled with tiny pin-prick size holes. Drops of sap and tiny "plugs" of sawdust are all over the branches and on the ground beneath. No bugs are visible, but as I standunder the tree I can actually hear chewing and see little bits of sawdust sifting down. Research on the internet makes me think it is the grubs of some kind of borer. Can anything be done to save the tree? Is there a recommended pesticide and can it be applied now? Thank you!
From your description it most likely your tree was has been attacked by one of the borers that attack pines possibly the southern pine beetle. Once the tree is infested management is limited to insecticides sprayed on the trees including the bark to protect them from an active infestation and possibly removing the infested tree. Several applications may be necessary to protect the trees. This is a protection spray and will not penetrate the bark to and kill the insects already in the tree.
The best recommendation is first to have the borer identified so that the proper action can be taken.
Contact the Oldham County Extension Service for help identifying the pest and recommendation for control and protection of other pines in the area.