Raspberry Beetle, Byturus Tomentosus

Raspberry beetle feeds at the stalk end of the blackberries, raspberries, loganberries. It is mainly a problem on summer-fruiting raspberries.

Though the beetle larvae are pests for Raspberry growers, adults can be found feeding on pollen on a variety of wildflowers. The small adults often congregate within flowers, particularly composites such as Dandelion. (Source: RHS Gardening)

Biology

Byturus tomentosus lays its eggs on the flowers of Raspberries, Blackberries and Loganberries. When the larvae hatch they eat the developing fruit. The 4mm (about 1/8in) long adult beetles are pale brown and they lay eggs on the flowers in May to mid-July. The young larvae feed at the stalk end of the developing fruit, but later move inside to feed on the central plug. In late summer, the fully-fed larvae move into the soil where they overwinter as pupae.

Nature of Damage

Damaged ripe berries have greyish-brown dried up patches at the stalk end. A brownish-white grub, up to 8 mm long, may be found inside the fruits.

Monitoring

Byturus tomentosus monitoring can be achieved by using Russell IPM’s Raspberry beetle lure PH-158-1PR with either a Mothcatcher trap or a Ferolite trap.