Hawthorn shield bug

Systematic position. The Hawthorn shield bug (Acanthosoma haemorrhoidale) belongs to the order Hemiptera and the family Acanthosomatidae. It is a common species found in woodland and garden habitats, known for its distinct shape and potential to damage cultivated plant species.

Affected crops. The pest primarily targets plants in the Rosaceae family. It is frequently observed on hawthorn, mountain ash, raspberries, blackberries, and various pome fruits, including apple and pear trees. Its feeding habits can cause significant distress to both ornamental bushes and fruit-bearing plants.

Biology and life cycle. Adults hibernate in sheltered areas such as leaf litter, tree bark crevices, or garden debris. As temperatures rise in spring, they emerge to feed on host plants. Females lay eggs in batches on the underside of leaves. Nymphs hatch and go through several developmental stages (instars) while feeding on sap, gradually maturing into adults by late summer.

Damage and harmfulness. The bug uses its piercing-sucking mouthparts to penetrate plant tissues. During feeding, the saliva injected into the fruit causes localized tissue death and structural deformation. This results in hardened, bumpy, and discolored areas on fruits, rendering them unmarketable and significantly reducing the overall yield quality.

Control measures. Integrated pest management (IPM) is crucial for controlling this bug. Sanitation practices, such as removing leaf litter and garden waste, reduce overwintering sites. If populations become high, selective insecticides can be applied during the early season. Maintaining a healthy garden ecosystem with beneficial predators like spiders and birds is also highly effective in keeping numbers low.