Willow aphid

The willow aphid (Pterocomma salicis) belongs to the order Hemiptera and the family Aphididae. It is a specialized pest that primarily targets woody plants, specifically focusing on various species of the Salix and Populus genera, often forming dense colonies on branches and trunks.

The damage caused by this insect involves the extraction of plant sap from the phloem of young branches and stems. This constant nutrient drain significantly weakens the host tree, leading to stunted shoot growth, potential deformation, and overall physiological stress.

Regarding its life cycle, the species overwinters in the egg stage, which are laid in crevices of the bark. Once spring temperatures rise, nymphs emerge and begin feeding. Throughout the growing season, multiple generations overlap, leading to rapid population expansion if conditions are ideal.

In addition to direct physical damage, these aphids secrete honeydew, a sugary substance that coats the surface of the bark and leaves. This creates an ideal environment for sooty mold to grow, which impairs the photosynthesis of the plant and reduces the aesthetic value of ornamental willow trees.

Management strategies require an integrated approach. Effective chemical control involves the use of systemic insecticides, especially when aphid populations reach economic thresholds. It is also highly recommended to encourage biological control by conserving populations of beneficial insects such as lady beetles and lacewings.

• Regular inspection of bark and young shoots in early spring.
• Pruning of severely infested and weakened branches.
• Application of systemic pesticides during peak activity periods.
• Enhancing tree vigor through proper irrigation and fertilization.