bug on my apple tree
This looks like a type of sphinx moth, probably a Hummingbird Clearwing. It does not have the mouthparts to damage your apple leaves, but instead visits flowers for nectar.
Apples can have several pests, but this time of year apple leaves look pretty ragged from a long season of wind and weather, etc.
This is an adult of the euonymus leafnotcher, Pryeria sinica, a recent asian import.
Adults emerge in October, mate, and lay eggs on euonymus. If you have euonymus, search for egg masses in winter and destroy.
Adults cannot feed, larvae feed on euonymus and celastrus. The species does not feed on apple and was merely resting there.