Birch flea weevil

Systematic position. The birch flea weevil (Rhynchaenus calceatus) belongs to the order Coleoptera and the family Curculionidae. These small beetles are known for their distinct jumping ability, facilitated by enlarged hind femora, which allows them to escape threats quickly and complicates visual detection during field monitoring.

Target crops. The pest is primarily associated with birch trees (Betula species). It is a common inhabitant of both wild forests and urban landscapes where birch is planted for ornamental purposes. In high-density populations, the beetle can cause significant aesthetic and physiological stress to host trees, affecting their overall health and longevity.

Biology and life cycle. Adult weevils overwinter in debris or under the bark of trees. In the spring, they emerge to feed on developing buds and leaves. Females lay eggs inside the leaf tissue. The larvae hatch and begin mining the leaf, feeding between the epidermis layers. After pupating inside the mine, the new generation of adults emerges to continue the cycle.

Damage and economic significance. Damage manifests in two ways: adult feeding, which creates small circular holes in the foliage, and larval mining, which results in large, irregular necrotic patches. Significant mining activity reduces the photosynthetic capacity of the tree, leading to premature leaf drop and weakening the plant, making it more susceptible to secondary pests or diseases.

Control measures. Integrated Pest Management (IPM) is crucial for controlling this weevil. Cultural practices, such as removing and destroying infested leaf litter in autumn, help reduce the overwintering population. In ornamental and nursery settings, chemical control via systemic insecticides applied early in the season can effectively prevent the establishment of the pest.

• Systemic insecticide treatments applied to tree crowns.
• Sanitary pruning and removal of infested foliage.
• Regular monitoring for early signs of leaf mining.