Codling Moth on Walnut Fruit
How to identify and get rid of codling moth on Walnut Fruit. Size: 15–20mm larvae; 20mm wingspan adult.
Identifying codling moth on Walnut Fruit
Small grey-brown moths with coppery wingtip markings; larvae are pinkish-white caterpillars with brown heads found tunnelled inside fruit.
Life cycle
Adults emerge in late spring and lay eggs on leaves and developing fruit. Larvae bore into fruit within days of hatching, feeding for 3–4 weeks before exiting to pupate. One to two generations per year depending on climate.
Damage to Walnut Fruit
Larvae tunnel into the fruit core, leaving frass-filled holes and causing premature fruit drop. Affected fruit is typically inedible at the core.
How to treat codling moth on Walnut Fruit
Remove and destroy infested fruit promptly. Use pheromone traps to monitor and reduce mating. Apply appropriately timed insecticide sprays or codling moth granulosis virus during egg-hatch periods.
Preventing codling moth on Walnut Fruit
Hang pheromone traps from early spring, wrap trunks with corrugated cardboard bands to trap overwintering larvae, and clean up fallen fruit and debris each autumn.