Willow red-gall sawfly

The willow red-gall sawfly (Pontania proxima) belongs to the order Hymenoptera and the family Tenthredinidae. This insect is widely recognized by the distinctive, colorful galls it induces on the leaves of host trees, primarily within the Salix genus.

Host plants typically include species such as crack willow, purple willow, and goat willow. While these galls rarely kill a mature tree, the aesthetic damage is significant, making the willow red-gall sawfly a problematic pest for nurseries, parks, and residential landscape planting where visual quality is essential.

The biological cycle is closely tied to the host's phenology. Adult females lay eggs in the leaf tissue during spring. As the larvae develop, they secrete chemicals that force the plant to grow a specialized gall structure. The larva remains inside this gall throughout its feeding stage, protected from external predators and environmental factors.

Symptoms are easily identified by the presence of rounded, often red or orange-tinged galls on the upper leaf surface. In cases of high infestation, the foliage becomes heavily distorted, which can lead to premature leaf drop and a reduction in the plant's overall photosynthetic capacity during the growing season.

Effective management strategies include the following:

• Sanitary pruning and destruction of heavily infested leaves to reduce the local population of the pest.
• Systemic insecticide applications applied precisely before the adult females begin egg-laying.
• Soil cultivation around the base of the trees in late autumn to disrupt the overwintering pupae hidden in the ground.
• Promotion of natural biodiversity, encouraging parasitic wasps that act as biological controllers of the sawfly larvae.