Raspberry beetle

The raspberry beetle (Byturus tomentosus) is a member of the order Coleoptera and the family Byturidae. This pest is a significant threat to commercial and garden raspberry plantations throughout Europe, causing substantial economic losses by affecting both the vegetative and generative parts of the plant.

The primary hosts of this beetle are species of the genus Rubus, specifically raspberries and blackberries. While they prefer these hosts, the beetles can also move to other blooming plants, including fruit trees, to feed on buds and young foliage when their preferred food source is not yet available.

The biology of the pest involves overwintering as adults in the soil at depths of 10 to 20 cm. In spring, when temperatures rise, they emerge and migrate to the shrubs. Females lay eggs inside the blossoms or on young fruit. The larvae emerge and tunnel into the ripening berries, feeding on the fleshy interior, which causes the berries to wither or rot.

Damage assessment reveals that infested berries become stunted, deformed, and rot prematurely. This makes the harvest unsuitable for fresh market consumption. Furthermore, the feeding activity of adult beetles on flowers results in significant pollination failure, leading to reduced overall fruit set and lower yield potential.

Integrated pest management (IPM) is essential for effective control. Cultural practices such as soil cultivation under the plants during the pupation stage significantly reduce the overwintering population. Chemical control should be strictly limited to the pre-flowering stage to prevent damage to pollinators while targeting adult beetles before they lay their eggs.