Web-spinning sawfly

The web-spinning sawfly (genus Neurotoma) belongs to the family Pamphiliidae within the order Hymenoptera. These insects are known as significant pests in orchards, as their larvae form characteristic silk webs that protect them while they feed on the foliage of host trees.

These pests primarily target deciduous fruit trees, including apples, pears, plums, and cherries. Larval feeding often starts on the leaves, where they build dense, messy nests made of silk and excrement, which can cover large portions of a branch in a short time.

The biology of the species typically involves a single generation per year. The larvae overwinter deep within the soil in earthen cells. As spring temperatures rise, the adults emerge, mate, and deposit eggs on the undersides of the leaves near the veins.

The damage caused by Neurotoma is primarily defoliation. In cases of high infestation, the larvae can consume almost all the leaf tissue, leaving only the main veins behind. This stress weakens the tree, reduces photosynthetic capacity, and ultimately negatively impacts fruit yield and quality.

Effective control measures require a combination of strategies. Monitoring the trees for early signs of web formation is critical. Once observed, manual removal is effective for small infestations, while larger populations may require the application of selective contact or systemic insecticides.

• Regular inspection of foliage during early spring for initial silk signs.
• Pruning and removing infested branches to prevent population spread.
• Cultivating the soil around tree bases to disturb overwintering larvae.
• Strategic insecticide applications targeted at the young larval stage.