Getting rid of this pest isn’t an easy task, because the span of time wherein this caterpillar is not inside a fruit is very short, and difficult to pinpoint.
It seems more relevant to sacrifice a few damaged fruits on the tree, to track the parasite’s developmental stage, without necessarily aiming to eliminate it entirely.
Eliminating it entirely feels practically impossible for the above-mentioned reason, anyway.
How to treat effectively against codling moth larvae
Beginning of May, spray an organic insecticide containing Bacillus thuringiensis (organic microbe-based insecticide) which works specifically against worms, and repeat this spraying two weeks later.
During the month of May, place pheromone traps to attract male moths, and reduce female fertilization rates.
Pick fruits up that have fallen before having reached maturity, since they have most often been invaded by codling moth caterpillars.
Sexual confusion is a technique that aims to mimic female hormonal scents with artificial pheromones. It makes it difficult for males to locate the females, which considerably reduces egg-laying.