Green leaf weevil

Polydrusus is a genus of broad-nosed weevils within the family Curculionidae (order Coleoptera). These beetles are easily identified by the metallic or iridescent scales that cover their bodies, providing effective camouflage against green foliage. In agricultural settings, they are considered significant pests of both deciduous trees and various shrub species.

The host range of Polydrusus is extensive, covering a wide variety of commercial crops. They frequently infest fruit trees such as apple, pear, plum, and cherry, causing severe damage to buds and developing foliage. Additionally, berry bushes like raspberries and currants are common targets, along with forest trees like oak, birch, and alder, which can be heavily affected in nursery environments.

The life cycle typically involves overwintering in the larval stage deep within the soil, where larvae feed on fine roots. As temperatures rise in spring, the larvae pupate, and the adults emerge to feed on above-ground plant tissues. This feeding phase is critical, as adults consume leaves and buds before mating and laying eggs in the soil near host plants.

Damage caused by Polydrusus is primarily aesthetic and physiological. The beetles chew the edges of leaves, creating jagged notches. When infestations are high, they can completely strip buds and soft shoots, preventing healthy tree growth and significantly reducing fruit yield. Weakened trees become more susceptible to diseases and environmental stress.

Effective management requires an integrated approach. Cultural controls, such as soil cultivation under the canopy during the late autumn, help disrupt the larval overwintering phase. If economic thresholds are exceeded during the growing season, professional chemical control using systemic or contact insecticides is recommended during the bud-burst and early flowering stages.