Question
Limbs look like they have been cut off by a beaver.  What do I do to get rid of this pest?   Thanks

Answer
They lay their eggs in the part of the limb cut off and on the ground. The way to reduce the population next year is to pick up all the fallen limbs and destroy them before the eggs hatch.
There is not a really good way to apply insecticides since the insects do not really feed on the limbs just cut them off after laying eggs  so a spray would net do any good. The good thing the overall health of the tree is not damage unless the population get so large that the majority of the limbs are cut. The destroying of the fallen limbs will greatly reduce the population that may hatch out next year. It may take a couple of years to see no more cutting but it will work.