Striped shield bug

The striped shield bug (Graphosoma rubrolineatum) belongs to the order Hemiptera and the family Pentatomidae. It is easily identified by its striking coloration, featuring longitudinal black stripes on a red background.

Adult insects reach a size of 10-12 mm. They possess a characteristic shield-shaped body and five-segmented antennae. The coloration serves as aposematism, a warning signal to predators about the bug's unpleasant odor and taste.

These pests primarily target plants within the Apiaceae (umbelliferous) family. They use their piercing-sucking mouthparts to feed on plant sap, particularly focusing on reproductive organs.

Key agricultural crops affected include carrots, parsley, celery, dill, and fennel. By attacking the peduncles and developing seeds, they significantly reduce the yield and quality of the harvest.

The striped shield bug completes one generation per year. Adults hibernate in sheltered areas, such as leaf litter, bark crevices, or dense dry vegetation, surviving the winter in a state of diapause.

They emerge in late spring or early summer to feed on early flowering plants. Mating and oviposition occur shortly after emergence, with the new generation becoming active throughout the mid-summer period.

The presence of the bug is marked by wilting of umbels and flower stalks. The punctures left by the bug's proboscis lead to necrosis and the cessation of seed development.

Visible signs include stunted growth of the flower clusters, drying of the seeds, and the distinct presence of the colorful adults gathered on the blossoms. High infestation levels typically result in poor seed germination rates.

Cultural control involves the removal of wild host plants like wild carrot or hogweed from the vicinity of fields. Regular weeding and maintaining field edges are crucial for preventing mass outbreaks.

Chemical control can be implemented using contact or systemic insecticides if population thresholds are exceeded. It is essential to ensure that applications are timed to avoid harming beneficial pollinators visiting the crops.