Emergence occurs over at least a 6 to 7 week period. Female moths will have mated and begun laying eggs within two days after emergence. The majority of eggs are deposited on upper and lower leaf surfaces, but some are deposited on twigs and fruit. Small, newly-emerged larvae immediately seek out the fruit into which they bore. After 3-4 weeks, fully matured larvae exit the fruit, spin their cocoon and pupate.
Moths emerge two weeks later and deposit eggs for the second generation.
Stings and deep entries are the two visible types of damage attributable to codling moth larval feeding. Deep entry damage occurs when larvae tunnel into and feed upon the developing seeds and flesh in apple cores. Newly emerged larvae seek protected sites under which they spin their cocoon. Larvae which congregate under these protected sites can be crushed. Further reduction of pest populations can be achieved via the removal of debris in and around orchard sites under which larvae would complete their lifecycles.