Raspberry Beetle Byturus ochraceus and Byturus tomentosus
Byturus ochraceus and Byturus tomentosus are the only two representatives of their family, the Fruit Worm Beetles, in Western Europe. The two species are very hard to tell apart, the difference being in the eyes and genitals. Usually however Byturus ochraceus is slightly bigger, darker and concentrates on plants of the Buttercup family, while the true Raspberry Beetle favoures Raspberries and other plants in the family of Roses. We believe it is Byturus ochraceus in the picture, because of the blackish head, and the fact they were photographed in a Buttercup. But adult Raspberry Beetles may visit Buttercups as well, so there is no certainty.
Both species are very small, brownish beetles. Byturus ochraceus measures 4 to 5 mm, the Raspberry Beetle usually 3 to 4 mm. The antennae end in a few thickened segments in a club like way. Adult beetles are best seen from April to June feeding on pollen in flowers, often in groups. The eggs of the Raspberry Beetle are deposited in May in the flowers or buds. They first feed on the small fruit, later move inside. It takes them 9 to 12 weeks to develop. Then they drop to the ground, where they dig a little hole in which they pupate. The pupa overwinters. A serious pest in Raspberry, Blackberry and modern crossings of the two, such as Loganberry and Tayberry. Byturus ochraceus behaves in about the same way, but it depsosits its eggs in members of the Buttercup family, so it is not considerd a pest.
Both species are very common all over Europe.
