Pear web-spinning sawfly

The pear web-spinning sawfly (Neurotoma flaviventris) is a member of the family Pamphiliidae within the order Hymenoptera. It is a recognized pest in fruit orchards that primarily targets pear trees but can also infest other Rosaceae species.

The host range includes pear, apple, plum, cherry, and mountain ash trees. The larvae are notorious for their social behavior, living in dense silk-spun webs, which give them their name and provide protection from predators and environmental factors.

The biology of this species is univoltine, meaning it has one generation per year. The larvae overwinter in the soil within earthen cells. During spring, they pupate, and adult sawflies emerge to lay eggs on the undersides of leaves, typically appearing during the flowering period of host trees.

Damage is caused by larvae feeding on the leaf tissue. A single colony can consume most of the foliage on a branch, leaving only the primary veins. This intensive defoliation significantly stresses the tree, reducing its vigor, fruit size, and the potential for next season's harvest.

• Cultural practice: Deep soil cultivation in autumn to disrupt the soil-dwelling overwintering larvae.
• Mechanical control: Pruning and destroying infested webbed branches before the larvae mature and drop to the ground.
• Chemical control: Targeted application of appropriate insecticides during the larval hatching period to minimize spread.
• Monitoring: Regular visual inspections of foliage during late spring to identify early-stage web nests.

Effective management relies on a combination of cultural and chemical strategies. By focusing on the overwintering stage and early larval activity, orchardists can successfully suppress populations of this pest without excessive pesticide use.