Hi Erin,

I'm not 100% certain of that insect's identity, but I doubt it is one that poses a threat to your apple tree. It does not resemble any of the major apple pests. 

It is most likely an insect that was just passing by, neither harming nor helping your tree. My best guess as to species would be the Marbled Fungus Weevil (Euparius marmoreus). These insects feed on fungus and decaying plant material. If my ID is correct, it doesn't necessarily mean that this beetle is feeding on decaying plant material/fungus associated with your tree. And even if it did, the insect itself would not be the source of the problem. If there was decay within your tree, that would be remedied by implementing proper cultural management practices (watering, pruning, fertilization, etc.).