Codling moth has many natural enemies but these are not sufficiently effective to regulate populations below damaging levels.
Insectivorous birds
Tits, especially, pick larvae and pupae in cocoons from bark crevices, but do not forage specifically for the pest unless population densities are very high and for this reason are of only limited value.
Egg parasites
The egg parasite Trichogramma can be introduced (4 releases of 2.5 m per ha have been shown to reduce damage by 50-80%) but such introductions are not cost effective. Ascogaster quadridentatus is a common, naturally-occurring parasite which lays a single egg in the codling moth egg but develops within the host larva.
Larval/pupal parasites
Many species of parasitic wasp attack codling moth larvae and/or pupae.
Predatory insects
Earwigs and predatory mirid and anthocorid bugs are known to feed on Codling moth eggs and young larvae.
Entomopathogenic fungi
Many species of entomopathogenic fungi, notably Beauveria bassiana, cause significant mortality in overwintered larvae and pupae.
Entomopathogenic nematodes
Neoaplectana carpocapsae are significant natural enemies of overwintering larvae/pupae on tree trunks, especially close to the soil surface.
Virus diseases
Codling moth granulovirus is usually associated with biocontrol applications though the virus can overwinter from one year to the next at a low level.