Woolly apple aphid

Systematic position: The woolly apple aphid (Schizoneura lanigera, also known as Eriosoma lanigerum) belongs to the order Hemiptera and the family Eriosomatidae. It is a major global pest of pome fruits, easily identifiable by the white, fluffy, wax-like filaments that cover its colonies on the bark of trees.

Host plants: The primary host is the apple tree (Malus domestica). While it shows a strong preference for apple, it can occasionally infest pear, cotoneaster, and hawthorn. The pest is particularly dangerous because it develops two forms: an aerial form that colonizes branches and a subterranean form that damages roots, which is difficult to detect and control.

Biology and life cycle: The lifecycle is characterized by asexual reproduction throughout the growing season. They overwinter as nymphs in cracks in the bark or on roots. As temperatures rise in spring, they become active and start producing large quantities of white wax to protect themselves from predators and environmental factors. Multiple generations are produced each summer.

Damage and pest status: The aphids feed by sucking sap from the phloem, injecting toxic saliva into the tree tissues. This causes abnormal cell growth, resulting in the formation of galls and cankers on branches and roots. These wounds weaken the tree structurally and make it highly susceptible to secondary infections like apple canker disease, often leading to stunted growth.

Protection measures: Management requires an integrated approach to maintain tree health:

• Utilizing resistant rootstocks to minimize root-level damage.
• Biological control using the parasitic wasp Aphelinus mali.
• Application of systemic insecticides during critical windows of pest activity.
• Good orchard hygiene, including pruning and removing heavily infested wood to reduce overwintering sites.