Apple clearwing moth

The Apple clearwing moth (Aegeria pyri) is a significant pest belonging to the order Lepidoptera and the family Sesiidae. As an adult, the moth mimics a wasp, a defensive mechanism that allows it to fly relatively undisturbed during daylight hours throughout the orchard.

This pest targets a wide range of pome and stone fruit trees, including apple, pear, cherry, plum, and quince. It is particularly attracted to trees that have existing bark damage, grafting scars, or pruning cuts, as these provide easy access for the larvae to reach the inner tissues.

The life cycle of the apple clearwing typically spans one or two years. Adult moths emerge from early summer through late summer. After mating, females deposit eggs on the bark. Upon hatching, the larvae burrow into the bark to feed on the cambium and phloem layers, constructing gallery systems that can severely disrupt the tree's vascular health.

Damage is often identified by the presence of frass (larval excrement) resembling fine sawdust emerging from cracks in the bark. Infested trees exhibit reduced vigor, premature leaf yellowing, and thinning canopies. In severe cases, the trunk or main branches can be girdled, leading to dieback or the eventual death of the entire tree.

Effective management and control strategies include:

• Maintaining tree health to ensure rapid healing of pruning wounds and mechanical injuries.
• Applying non-toxic wound dressings or sealing agents to protect exposed wood.
• Using pheromone traps for monitoring moth flight and mating disruption.
• Targeted insecticide applications during the egg-laying and larval emergence window.
• Removing and destroying heavily infested branches to reduce the overall pest population in the orchard.