Pear shoot sawfly

Taxonomic position. The pear shoot sawfly (lat. Janus piri) belongs to the order Hymenoptera and the family Cephidae. It is a specialized pest that specifically targets pear trees, often causing notable economic losses in orchards and nursery settings if left unchecked.

Host plants and damage. The primary host for this pest is the pear tree. The damage is primarily observed on young, vigorous shoots. The presence of the pest is indicated by the wilting and subsequent drying of the shoot tips, caused by the adult female's act of girdling the stem during oviposition.

Biology and life cycle. Janus piri typically completes one generation per year. Larvae hibernate within the infested shoots, where they pupate in the spring. Adult sawflies emerge around the time of bud burst and flowering. Once mated, the females insert their eggs into the soft tissue of the new growth.

Economic impact. The larvae feed internally, boring into the pith of the shoot. This feeding behavior disrupts the vascular system, causing the tip of the shoot to blacken, curl, and break off. Severe infestations significantly reduce the growth of young trees, disrupting their shape and weakening overall tree health.

Control measures. Integrated pest management (IPM) is essential for controlling this sawfly:

• Mechanical removal and destruction of infested shoots before the larvae emerge.
• Application of systemic insecticides during the sensitive stage of bud development and early shoot growth.
• Monitoring adult flight activity using traps to determine the optimal timing for chemical interventions.