To deal with codlin moth you first need to know their life cycle, then find the strategy to organically control them.
Life cycle (Southern Hemisphere, NZ season)
Egg - Adult mating then female lays egg during Nov-Feb. (single egg, 1mm size, on leaf near fruit)
Larvae - main damage done to fruit during Nov-April (20mm size, feeding on apple with tunnel damage)
Pupae - overwintering (cocoons under bark, wood pile etc)
Adult - Nov-Jan
- Pheromone trap (available at garden centres)
Purpose: to minimise mating. Use synthetic female codlin moth hormone lure to attract and trap male on a sticky board.
Method: hang the trap on the side branch close to main trunk
- Tea of wormwood and tansy.
Purpose: To avoid mating. The smell of tea can cause the adults to avoid mating.
Method: Cook tea of wormwood and tansy, spray tea all over the tree - trunks, branches, leaves, fruits, etc.
Recipe: Pick some fresh leaves before plant has reached flowering stage. Add enough water to cover and bring to boil. Strain when cool. Dilute one part mixture to four parts water to use. Do not use to frequently, nor too strong a solution on tender vegetables as it may retard natural growth.
Purpose: To remove pupae. The larvae will hide into cardboard then over-winter in pupae form.
Method: Wrap corrugated cardboard on all the branches close to main trunk. At end of winter, remove it and destroy.
Cleaning bark, hygiene (remove litters, etc)
The US National Sustainable Agriculture Information Service article on Organic and Low-Spray apple production has more information about codlin moth with organic solutions included.