Leaf weevil

The leaf weevil (Polydrusus impressifrons) belongs to the order Coleoptera and the family Curculionidae. It is a common pest that primarily affects deciduous trees and shrubs, often going unnoticed due to its cryptic behavior, but capable of causing significant foliar damage during outbreaks.

This beetle species targets a variety of plants, including common orchard crops like apple, pear, and plum, as well as forest trees such as birch and willow. The adults are known for feeding on the foliage, which can cause severe stress to young saplings and nursery plants, potentially retarding their growth if infestations are not controlled.

The life cycle of this weevil involves both subterranean and above-ground stages. Females deposit eggs on foliage or within bark crevices, and upon hatching, the larvae drop to the soil. The larval stage is spent underground, where they feed on the root systems of host plants. Overwintering typically occurs in the soil, allowing the insect to survive harsh winter temperatures.

The damage caused by Polydrusus impressifrons is characterized by irregular or scalloped edges on the leaves. When populations are high, the beetles can cause near-complete defoliation, which severely hampers the tree's ability to photosynthesize. Such stress makes trees more susceptible to secondary infections or environmental damage like drought.

Integrated pest management strategies are essential for controlling this beetle:

• Cultivating the soil beneath the canopy to disturb and destroy overwintering larvae.
• Applying registered insecticides during the emergence of adult beetles in spring.
• Using sticky bands on the tree trunks to prevent beetles from climbing into the crown.
• Promoting biodiversity in the orchard to encourage natural predators, including birds and predatory insects.