Poplar bark aphid

Systematic position: The poplar bark aphid, Phloeomyzus passerinii, belongs to the order Hemiptera and the family Aphididae. It is a specialized pest that lives primarily underneath the bark of host trees, making it difficult to detect during the early stages of an infestation.

Crops: This insect primarily infests various species of the genus Populus, particularly black poplar (Populus nigra) and white poplar. It is a major concern for short-rotation forestry and nurseries where wood production is the primary goal.

Biology and lifecycle: The aphid colonizes the trunks and larger branches of host trees. They overwinter as nymphs within bark crevices. As temperatures rise in spring, the colonies expand, and they produce multiple generations throughout the growing season, including both wingless and winged forms to facilitate the spread to neighboring trees.

Damage characteristics: By feeding on the phloem sap, the aphids cause severe localized damage to the bark and cambium. The infested areas exhibit swelling, cracking, and necrotized bark. Chronic infestations significantly weaken the tree, leading to stunted growth, loss of wood quality, and increased susceptibility to secondary infections by wood-decay fungi.

Control measures: Management strategies emphasize the use of resistant cultivars as the most sustainable approach. Monitoring programs should be implemented in plantations to detect aphid activity early. In commercial nurseries, the application of systemic insecticides during the nymph emergence period is effective, while sanitation methods, such as removing heavily infested trees, help reduce the overall pest pressure.