Green leaf weevil

The green leaf weevil, scientifically known as Phyllobius calcaratus, is a representative of the order Coleoptera and the family Curculionidae. This species is commonly found across various ecosystems, acting as a significant pest that affects both wild deciduous trees and numerous cultivated agricultural plants.

This insect has a wide host range, feeding on various broad-leaved trees like alder, birch, and hazel. Among cultivated plants, it frequently attacks fruit trees such as apple and pear, as well as several berry crops and legumes. Its ability to feed on diverse species makes it a persistent threat in many horticultural settings.

The lifecycle of this pest is closely tied to the soil, where the larvae spend their developmental stage. Larvae feed primarily on the roots of plants, which can cause significant stunted growth in young saplings. After pupation in the soil, the adults emerge to feed on the foliage, coinciding with the spring growth flush of the host plants.

The damage caused by the adults is typically recognized by the scalloped edges on leaves, created as they feed along the leaf margins. Heavy infestations lead to significant leaf loss, which reduces the plant's photosynthetic capacity and weakens its overall vigor. In severe cases, constant feeding leads to defoliation, affecting fruit yield and quality.

Control strategies should focus on both physical and chemical interventions. Cultivation and tillage of the soil beneath host plants in late autumn can effectively destroy the overwintering larvae. During the peak emergence of adults, systemic or contact insecticides are recommended to minimize damage during the critical early growing stages of the crops.