Woolly aphid

Systematic position: The Woolly aphid (Eriosoma lanigerum) belongs to the order Hemiptera and the family Aphididae. It is a highly specialized pest known for its white, cotton-like waxy secretions that cover the colony, making them easy to identify on infested trees.

Host plants: The primary host for this pest is the apple tree (Malus domestica). In addition to apple, it may occasionally infest pears, quince, and other members of the Rosaceae family. The aphids prefer to feed on young shoots, pruning cuts, bark crevices, and roots.

Biology and lifecycle: The species reproduces parthenogenetically throughout the growing season, producing multiple generations. They overwinter as nymphs in protected sites such as bark cracks or on the roots. As temperatures rise in spring, the colonies multiply rapidly, and adults secrete the characteristic white filaments.

Type of damage: Feeding activities cause the formation of abnormal tissue swellings known as galls. These galls interfere with sap flow and nutrient transport, leading to tree stunting, branch dieback, and reduced fruit quality. Severe infestations can significantly weaken young trees or even lead to their death.

Control measures: Integrated pest management (IPM) is crucial. Key strategies include:

• Regular pruning and destruction of infested branches.
• Application of systemic insecticides during active growth periods.
• The use of resistant rootstocks.
• Biological control by introducing the parasitoid wasp Aphelinus mali.