Pied shieldbug

Systematic position. The pied shieldbug (Sehirus bicolor) is a member of the order Hemiptera and the family Cydnidae, commonly known as burrower bugs. It is recognized by its distinct black and white coloration and is widely distributed across various habitats in Europe and temperate regions.

Crops affected. This species primarily feeds on plants within the Lamiaceae family, such as dead-nettles. However, in agricultural and garden settings, it may cause damage to various soft fruits, including strawberries and raspberries. It uses its piercing-sucking mouthparts to extract plant sap from leaves and developing buds.

Biology and life cycle. Sehirus bicolor undergoes a hemimetabolous development cycle consisting of eggs, five nymphal instars, and adults. Adults typically overwinter in the soil or under leaf litter. With the arrival of spring, they emerge to mate and lay eggs, leading to the development of nymphs that progress through several molts during the summer months.

Nature of damage and pest status. Feeding by adults and nymphs causes chlorosis and wilting in host plants. When these bugs attack berry crops, they can cause fruit deformation and general plant stress, which eventually leads to a decrease in yield and quality. Their presence is particularly noticeable in gardens and small-scale farms with high vegetation diversity.

Protection measures. Managing populations of the pied shieldbug requires a combination of preventative and corrective strategies:

• Effective weed control, specifically targeting Lamiaceae species in the vicinity of crops.
• Soil cultivation in autumn to disrupt overwintering sites for adult bugs.
• Sanitation practices that remove debris where insects hide during the dormant season.
• Judicious use of chemical control methods only when pest density reaches levels that threaten crop profitability.