Here's a very simple method that we used with a large codling-infected persimmon tree. Over winter, the larvae drop to the ground around the tree. They become active in spring, moving upward to infect fruit. So simply stop them from doing that by laying cardboard sheets (or similar) to cover the ground completely under the tree as early as possible. This is immediately successful in slowing down infestation but it usually takes around 3 years of doing this consistently, (ie, early each spring) to get rid of them totally.
