Elm gall aphid

Systematic position: The elm gall aphid (Tetraneura ulmi) belongs to the order Hemiptera and the family Aphididae. It is a heteroecious aphid, meaning it alternates between a primary woody host and a secondary herbaceous host during its life cycle.

Damaged crops: The primary host is the elm tree (Ulmus species), where the aphids create distinctive galls. The secondary hosts consist of various grasses and cereal crops, such as wheat, barley, and oats, which suffer from aphid infestation on their root systems.

Biology and life cycle: Eggs overwinter in the bark crevices of elm trees. In spring, larvae emerge and cause the formation of leaf galls. By early summer, winged forms migrate to the roots of grasses, where they reproduce parthenogenetically. In the autumn, a return migration to the elm trees occurs to deposit overwintering eggs.

Damage and harmfulness: On elm trees, the aphid causes the formation of large, comb-like galls, leading to leaf distortion. On cereals, the aphids congregate on the roots and suck plant sap. This infestation significantly weakens the plants, hinders nutrient uptake, and causes a reduction in both grain quality and total yield.

• Implementing spatial isolation between cereal fields and elm-populated areas.
• Applying systemic insecticides when migration to cereal roots is detected.
• Maintaining field hygiene by eliminating grassy weeds that serve as alternative hosts.
• Monitoring the roots of cereal crops during the mid-summer period.
• Employing cultivation practices that support plant vigor against root stress.