Identifying the insect in your apples is an important step in making a treatment plan. You might even have both codling moth and apple maggot, and though pesticides for the maggot are also listed for the moth, you have to watch the timing listed for each. Use sticky traps to monitor the flying adult population. You’ll find information here, in EC 631. There is a lot of useful general information about pest control in home orchards, and the link at left on the first page  can jump you to the apple section.
WSU has a guide to tell if you have codling moth or apple maggot, here.
Sanitation around fruit trees is a critical insect and disease control step. See a this prior Q&A for details.