Buck moth

The Buck moth (Hemileuca maia) is a species of moth belonging to the family Saturniidae. While often studied for its interesting behavioral ecology, it is also recognized as an occasional defoliating pest of forest trees, particularly in parts of North America.

The primary host plants for the larvae are species within the genus Quercus (oaks). However, the larvae are also known to feed on willow (Salix) and various other deciduous trees and shrubs, which can lead to economic losses in timber production or amenity tree management.

The life cycle is univoltine, meaning there is only one generation per year. Adult moths emerge in the late autumn, mate, and deposit eggs in clusters on the twigs of host plants. The eggs overwinter and hatch in the spring, coinciding with the flushing of leaves, allowing the larvae to immediately begin feeding.

Larval feeding causes significant damage through defoliation. A large population of caterpillars can strip an entire tree of its leaves, which reduces the tree's vigor, hinders growth, and can make the plant more susceptible to opportunistic pathogens or secondary insect infestations during subsequent seasons.

Effective management strategies rely on integrated pest management (IPM) practices. This includes monitoring for egg clusters on branches during the dormant season, applying biological control agents such as Bacillus thuringiensis when larvae are young, and utilizing targeted insecticide applications if population densities reach critical economic thresholds.