The adult codling moths lay their eggs on or near developing fruit. These eggs hatch into small white caterpillars, which eat their way into the fruit and feed inside while it's developing. The caterpillars may be found inside the fruit at harvest time, but have usually eaten their way out to overwinter on the bark of the tree. They will then pupate and hatch into adult moths the following spring, ready to mate.
Holes often visible in ripe fruit. When the fruit is cut open, the tunnel made by the maggot-like caterpillar will be seen, lined with its droppings or frass.
Find it on
apples, pears, quince, walnuts
Remove infected fruit as soon as any damage is evident to limit overwintering caterpillars. Control is available in the form of pheromone traps that catch male moths in April and May.