Feathered Thorn

The Feathered Thorn (lat. Colotois pennaria) is a moth belonging to the family Geometridae and the order Lepidoptera. It is a well-known pest in temperate regions, frequently impacting both wild woodland trees and managed orchards due to the feeding habits of its larvae.

The moth species targets various deciduous trees. Its primary hosts include fruit-bearing trees such as apple, pear, plum, and cherry. It also thrives on forest species like oak, birch, and hazel. The larvae cause the most damage during the early spring by consuming expanding buds and fresh foliage.

The life cycle is univoltine, meaning there is one generation per year. Adults are active in the autumn months, typically appearing between September and October. The females deposit their eggs on twigs and stems, where they remain throughout the winter before hatching as the spring weather begins.

The damage caused by the larvae is characterized by defoliation. As the caterpillars grow, they consume significant amounts of green matter, which can lead to weakened tree vigor and reduced fruit yields. In cases of high infestation, the entire canopy of a tree may appear sparse or damaged.

• Monitoring adult flight in autumn.
• Application of sticky bands on tree trunks.
• Using biological controls like Bacillus thuringiensis.
• Targeted insecticide sprays during egg hatch.
• Promoting biodiversity to encourage bird predation.

Managing the Feathered Thorn requires a combination of vigilance and timely intervention. By inspecting trees in early spring for signs of larval feeding and maintaining healthy orchard hygiene, growers can mitigate the risks posed by this moth and ensure the long-term productivity of their fruit trees.