Lesser willow psyllid

The Lesser willow psyllid (scientific name: Trioza minuta) is a small insect belonging to the order Hemiptera and the family Triozidae. These sap-sucking pests are recognized for their impact on willow trees, where they feed by extracting vital fluids, causing structural damage to the host plant.

The primary hosts for Trioza minuta are members of the Salicaceae family, particularly willow species. The insect is widely distributed and can cause significant aesthetic and physiological damage to trees in forest nurseries, ornamental gardens, and riparian landscapes.

The biology of this pest involves several life stages: egg, nymph, and adult. Adults typically overwinter in protected areas, emerging in early spring to deposit eggs on the developing buds and young leaves. The nymphs settle on the leaf underside, where they feed and develop, often triggering rapid population growth.

The feeding activity of Trioza minuta nymphs leads to the formation of galls and leaf deformation. As they pierce plant tissue, they inject toxins that cause leaves to curl, yellow, and occasionally drop prematurely. This damage reduces the tree’s photosynthetic capacity and weakens overall plant health.

Integrated pest management strategies are recommended to mitigate damage:

• Applying systemic insecticides in early spring to target emerging nymphs before they cause extensive damage.
• Pruning infested shoots and branches to reduce the pest population density in the garden or nursery.
• Encouraging natural predators such as ladybugs, lacewings, and parasitic wasps that control psyllid populations.
• Ensuring healthy growing conditions to improve the natural resistance of the host trees against pest outbreaks.