Small spruce sawfly

The small spruce sawfly (lat. Pristiphora abietina) belongs to the order Hymenoptera and the family Tenthredinidae. This insect is a significant defoliator, primarily affecting Norway spruce (Picea abies) in European forest ecosystems and ornamental nursery sites.

The host range is narrow, with the larvae feeding exclusively on the fresh needles of spruce trees. They show a strong preference for young, developing shoots, which makes young spruce plantations particularly susceptible to damage during the spring growth period.

The life cycle is univoltine, meaning one generation occurs per year. The insect overwinters as a prepupa within a cocoon in the soil. Adults emerge in spring, coinciding with the flushing of the host tree buds. Females lay eggs in the soft needles, ensuring immediate food availability for the larvae.

Damage is caused by the larvae consuming the young needles. The infested needles typically become deformed, chlorotic, and eventually drop prematurely. Severe infestations result in extensive defoliation, which significantly reduces the tree's annual growth and makes it susceptible to secondary pest attacks.

Effective management strategies combine chemical and biological approaches. Chemical control is most effective when targeted at the early larval stages immediately after bud burst. Integrated Pest Management (IPM) practices focus on monitoring adult activity and ensuring the overall health and vigor of the tree population.

• Monitoring adult flight using sticky traps.
• Applying systemic insecticides during early larval development.
• Biological control using natural predators and parasitoids.
• Maintaining high biodiversity in forest stands to encourage natural enemies.