Willow-poplar aphid

Systematic position: The willow-poplar aphid (Pterocomma bicolor) belongs to the order Hemiptera and the family Aphididae. It is a well-known specialist pest that targets trees within the Salicaceae family, specifically focusing its life cycle around willow and poplar species.

Host plants: This aphid species primarily infests various willow (Salix) species and, to a lesser extent, poplars (Populus). It colonizes young shoots, twigs, and bark, using its piercing-sucking mouthparts to feed on the sap of the host plant throughout the growing season.

Biology and life cycle: Pterocomma bicolor overwinters in the egg stage, typically deposited on the bark of host trees. In the spring, nymphs hatch and begin feeding immediately. The species undergoes several generations throughout the summer, including winged forms that allow the population to disperse and colonize new, healthy trees in the vicinity.

Nature of damage and harmfulness: Feeding by these aphids causes significant stress to the host tree, manifesting in stunted growth, leaf curling, and shoot deformation. Furthermore, the excretion of honeydew promotes the growth of sooty mold, which interferes with photosynthesis and damages the aesthetic appearance of landscape trees.

Control measures: Integrated pest management (IPM) is essential for controlling Pterocomma bicolor. Key strategies include:

• Regular monitoring of bark and young shoots starting in early spring.
• Applying systemic insecticides when aphid colonies are first detected.
• Encouraging natural predators such as lady beetles and lacewings.
• Removing severely infested branches to reduce the overall population pressure.