They then exit the fruit, seek shelter, spin a cocoon, and may or may not pupate. Some first-generation larvae do pupate, emerge as adults in 2 to 3 weeks at about the fourth or fifth cover spray, and produce a second generation. The majority of the second generation overwinter as mature larvae. Individuals of the second generation may also pupate and attempt to produce a third generation at the seventh or eighth cover spray. This generation, which does not survive the winter, is termed a suicide generation.
Individuals can, however, inflict additional late-season fruit injury.
Stings are caused by early instar larvae that have been poisoned and die shortly after puncturing the apple skin. Larvae that feed on the core characteristically leave frass exuding from the point of entry. Stings lower the value of the fruit from fresh market to processing grade apples. Tunneling causes the fruit to be rejected. Monitoring and management Pheromone traps for monitoring populations of adult male codling moths can be used to determine if and when controls are necessary.