Female codling moths lay their eggs on fruit and leaves of the apple and pear tree. The eggs hatch in 6 to 14 days. The caterpillars start tunneling into the fruit within 24 hours. They tunnel through the fruit to get to the seeds which is their preferred food. When full grown the caterpillars tunnel back out of the fruit and spin a cocoon in the bark or debris at the base of the tree where they pupate over the winter.
The larvae of the codling moth tunnels into fruit and makes apples wormy. It is the most significant insect pest of apples and pears, and is sometimes found in cherries, peaches and crab apples. The larvae create tunnels in the fruit with brown moth excrement at the entry and exit point of the tunnels.
Cocoons hidden under loose scales of bark and in the soil or debris around the base of primarily fruit trees.