Willow hairy aphid

Systematic position. The willow hairy aphid (Pterocomma pilosum) belongs to the order Hemiptera and the family Aphididae. It is a specialized pest primarily associated with host plants in the Salicaceae family, specifically those in the Salix and Populus genera.

Host plants and damage symptoms. This aphid feeds on the sap of willow and poplar trees. Infestations are typically found on young twigs, branches, and stems. Symptoms of damage include wilting of new shoots, deformation of leaves, and yellowing foliage, which weakens the host tree's vigor.

Biology and life cycle. The life cycle involves multiple generations per year. The species overwinters in the egg stage, which is usually deposited in bark crevices or near buds. As spring temperatures rise, nymphs hatch and begin feeding on the developing sap, rapidly increasing their population through asexual reproduction.

Economic impact. Heavy infestations can lead to significant physiological stress in trees. The excretion of honeydew by the aphids promotes the growth of sooty mold, which covers the leaf surface and branches, interfering with gas exchange and photosynthesis, leading to reduced tree growth and health.

Protection measures. Integrated Pest Management (IPM) is essential for control. Strategies include:

• Pruning and destroying highly infested branches during the early season.
• Encouraging natural predators such as lady beetles, lacewings, and hoverflies.
• Applying systemic or contact insecticides when aphid density reaches economic damage thresholds.