Maples often get flat headed apple tree borer (if Primary) they also get a lot of borers that live in the dead wood and bark - There is no spray for the latter type. The primary borers are there because your tree is stressed for some reason. You need to solve the stress problems or the spray will be almost useless. Find imidacloprid with a borer label to control the borers and follow all label directions and precautions on the label.
