Cape Cod Tree Pests
The turpentine beetle, attacks local pines by boring into the trunk, eventually killing the tree. Bore holes can be seen on the trunk and usually have sap oozing from them.
The Crypt Gall Wasp lays its larvae in the ends of branches of the black oak creating galls that eventually kill the branch, due to the large numbers of Gall Wasps over the last few years entire trees are dying and in some cases large swaths of trees are dying.
Links to information on both of these pests are readably available, for example:
Here’s a PDF you can download about the Crypt Gall Wasp.
Gypsy Moths, a defoliating caterpillar can essentially clear a tree of all of it’s leaves if present in large numbers. The defoliation caused by gypsy moths seldom kills a tree the first year, but can stress it and make it vulnerable to drought and disease. Repeated years of gypsy moth infestation will likely kill trees. Oaks seem to be the food of choice but other broad leaf trees are also at risk.