Plum moth

The Plum moth (Illiberis pruni) is a lepidopteran insect belonging to the Zygaenidae family. As a specialized phytophage, it poses a significant threat to various stone fruit trees, often causing economic losses in both commercial orchards and home gardens throughout its range.

This pest primarily attacks host plants within the Rosaceae family. Its main targets include plum, apricot, peach, cherry, and almond trees. The presence of the pest is often correlated with dense orchard planting patterns, which provide ideal conditions for the moth’s life cycle and development.

The biological cycle of Illiberis pruni involves overwintering as early-stage larvae (caterpillars) in silken cocoons tucked into bark crevices or near bud scales. As temperatures rise in early spring, the larvae emerge, coinciding with the swelling of buds. They feed aggressively on vegetative and reproductive plant parts.

Damage assessment reveals that the caterpillars cause primary injury by consuming buds, preventing proper flowering. Subsequently, they move to the foliage, performing skeletonization, which reduces the photosynthetic area of the tree. Severe infestations lead to canopy thinning, impaired tree vigor, and a considerable decrease in overall fruit production.

Integrated pest management (IPM) is essential for controlling this moth. Cultural practices, such as scraping loose bark to destroy overwintering sites and maintaining proper tree pruning, are highly effective. When necessary, targeted application of insecticides during the larval emergence period provides sufficient protection to prevent major damage to the orchard.