Protect Apples and Pome Fruits from Codling Moth Infestation

Adult codling moths are small gray-brown moths, about ½ inch long, with distinctive coppery bands at the tips of their wings.

The real damage, however, comes from their larvae—cream-colored caterpillars with brown heads that burrow into developing fruit. Infested apples or pears often show tiny entry holes with sawdust-like frass on the surface, and when cut open, the core reveals tunneling and feeding damage. Early signs in the orchard include premature fruit drop and clusters of damaged fruit near the tops of trees.

Pheromone mating disruption works by flooding the orchard with synthetic copies of the female codling moth’s sex pheromone. Male moths are unable to locate females, which reduces mating and lowers the number of larvae that damage fruit.

Decades of research confirm the effectiveness of this approach:

• Roelofs et al. (1971) showed males are strongly attracted to the identified pheromone compounds.

• Barnes et al. (1992) and Howell & Knight (1992) demonstrated that pheromone dispensers placed in orchards significantly reduced mating and fruit injury.

• Knight (1995) and Judd (1996) confirmed that commercial dispensers could suppress codling moth populations at a large scale in apples and pears.

• Today, pheromone disruption is applied on roughly 90% of Washington apple acreage (WSU Tree Fruit Guide), reducing insecticide use and supporting sustainable pest management.

The most effective and sustainable way to control codling moth is through pheromone-based mating disruption.

By placing dispensers throughout the orchard, the air is saturated with the female sex pheromone, confusing males and preventing successful mating. This reduces the number of larvae that tunnel into fruit and lowers the need for repeated insecticide sprays.

For best results, mating disruption should be applied at the start of the moth’s flight and maintained across the entire block, ideally in combination with monitoring and integrated pest management practices.