Dogwood borer

The dogwood borer (Synanthedon corni) is a species of clearwing moth belonging to the Sesiidae family in the order Lepidoptera. This insect is a significant internal borer that mimics the appearance of wasps, which serves as a natural defensive adaptation against potential predators in the orchard environment.

These moths primarily infest trees in the genus Cornus (dogwood), but they also pose a serious threat to various fruit trees including apples, cherries, and plums. The larvae target the cambium layer, focusing their activity on the trunk and the base of major scaffold branches where the bark is thickest.

The life cycle involves an egg stage, larval stage, pupation, and the adult phase. After hatching, the larvae immediately bore into the bark, constructing galleries that severely disrupt the tree's vascular system. The larval stage is responsible for all the structural damage observed in host trees.

Damage assessment reveals signs of larval presence, such as frass deposits (wood dust and excrement) protruding from holes in the bark, peeling or cracking bark, and sometimes crown dieback. Continuous larval feeding reduces the tree's vigor, lowers fruit production, and creates entry points for fungal diseases and other secondary pathogens.

Integrated pest management strategies are essential for controlling populations of this borer:

• Maintaining tree health through proper fertilization and irrigation to improve natural defense.
• Applying physical barriers or trunk wraps to prevent female moths from laying eggs on the bark.
• Using pheromone traps for monitoring moth activity and mass trapping.
• Applying targeted insecticide applications timed precisely with the adult flight and egg-hatch periods.
• Ensuring proper orchard sanitation by removing and destroying heavily infested branches.