Two years ago, we had a severe infestation of Jack Pine Budworms on all of our mugo pines - about 7 in all - leaving them looking awful. We sprayed them with a concoction of hot pepper powder and soap, but the branches were left black. This past year our 10-year-old Jack pines were infested with the same worms and now two of them have died over the winter - only the yellow needles and black branches and trunk left. Help so we don't lose the other eight??
Get hold of an arborist. They can asess the damage remove the diseased treees and either recommend or apply an insecticide that can control the worms and perhaps the secondary infection that occurs in the trees as a result of the worm damage. Thurcide comes to mind for this problem. To my knowledge, there are no natural remedies for this other than a good old cold snap which is probably too late for your trees. Regards Bob