Cherry web-spinning sawfly

Systematic position. The cherry web-spinning sawfly (Neurotoma fasciata) is a member of the order Hymenoptera and the family Pamphiliidae. It is a well-known specialist pest that can cause significant localized damage to fruit orchards throughout its range.

Host plants and damage. This species primarily targets stone fruits, particularly cherries (both sweet and sour) and plums. The larvae are colonial and feed on foliage by weaving silk threads to create web-nests, which serve as both a shelter and a food source during their larval development.

Biology and life cycle. The life cycle involves a single generation per year. The insect overwinters as a prepupa in the soil. Adults emerge in spring, coinciding with the flowering of their host trees. Females lay eggs on the undersides of leaves, and upon hatching, the larvae work collectively to construct silk webbing.

Host damage and economic impact. The feeding activity of the larvae results in the skeletonization of leaves, as they consume the leaf tissue while leaving the veins intact. Extensive defoliation weakens the trees, leading to reduced vigor, lower fruit quality, and increased susceptibility to other environmental stressors or diseases.

Protection measures. Integrated pest management for this species involves both physical and chemical interventions. Key practices include:

• Cultivating the soil beneath the canopy to disturb overwintering sites.
• Manual pruning and destruction of infested branches with web-nests.
• Application of selective insecticides during the early larval stage before nests become too dense for spray penetration.
• Monitoring adult flight activity using sticky traps to determine the optimal timing for protective treatments.