Hawthorn aphid

Systematic position: The hawthorn aphid (Prociphilus crataegi) belongs to the order Hemiptera and the family Aphididae. It is a highly specialized species recognized for its unique gall-forming behavior on its primary host plants.

Host plants: The primary host for this aphid is the hawthorn tree (Crataegus). However, the aphid is migratory, meaning it spends a significant portion of its life cycle on the roots of various grass species (Poaceae), which serve as secondary hosts.

Biology and life cycle: The insect exhibits a heteroecious life cycle. In spring, stem mothers hatch from overwintered eggs on hawthorn branches. After producing several generations, winged forms migrate to the roots of grasses. In autumn, they return to the hawthorn trees to mate and lay eggs for the winter season.

Damage and harm: The most visible damage occurs on hawthorn leaves. The feeding activity of the aphids causes the leaves to curl, thicken, and develop unsightly galls. This deformation hinders the leaf's ability to photosynthesize, leading to premature leaf drop and overall tree stress.

Protection measures: Control is most effective when targeted at the early spring stage before the galls form. Applying dormant oils or systemic insecticides during the bud burst stage helps to minimize early infestation. Additionally, removing nearby grasses and weeds can significantly disrupt the aphid's migration cycle.

• Applying systemic insecticides during early spring.
• Mowing or removing grass weeds around hawthorn trees.
• Pruning and destroying heavily infested twigs to reduce population.
• Encouraging biological control agents like lady beetles and lacewings.