Small worm type in tree causing limp browning. How do I save my white pines from this grub type larva from killing my 6' newly planted trees?
White Pine Insect Infestation
Certified GKH Gardening Expert
That sounds like Pine Sawyer beetles. They are very difficult to control once symptoms are obvious. I would contact the nursery you purchased these trees from and explain your problem.
Here is an article about them and a few other borers;