Poplar-auricula aphid

Systematic position: The Poplar-auricula aphid (Thecabius auriculae) belongs to the order Hemiptera and the family Aphididae. It is a highly specialized species that requires specific hosts to complete its complex biological life cycle, alternating between woody and herbaceous plants.

Host plants: The primary host is the poplar tree (Populus), where the aphid induces the formation of leaf galls. The secondary hosts are various species of the Primulaceae family, such as Primula, as well as Luzula, where the aphid colonies settle on the root systems during the summer months.

Biology and lifecycle: The lifecycle involves overwintering as eggs on poplar bark. In spring, stem mothers emerge and induce gall formation on leaves. As the season progresses, winged forms develop and migrate to the roots of herbaceous plants, where they continue to reproduce parthenogenetically until autumn.

Damage and harm: On poplar trees, the aphid causes the leaves to curl, thicken, and form protective galls, which reduces the photosynthetic capacity of the tree. On primulas and other secondary hosts, the aphids feed on the roots, causing stunted growth, leaf chlorosis, and a general decline in the plant's health.

• Applying systemic insecticides on poplars during early bud burst.
• Treating the soil around vulnerable primula plants with suitable systemic insecticides.
• Removing infected leaves from poplars early in the season to reduce population buildup.
• Promoting natural predators like ladybirds and hoverflies in the garden ecosystem.
• Ensuring proper spacing and avoiding dense planting to improve airflow.