Photo: Pjt56 / CC BY-SA 4.0

Osmia cornuta

European Orchard Bee

A large and early-flying mason bee (10–15 mm) with a black head and thorax, rust-red hairy abdomen, and two small horn-like projections on the female clypeus. It is one of the first bees to emerge in late winter (February–March) and a highly effective pollinator of stone fruit and pome fruit trees. It nests in pre-existing cavities, sealing cells with mud. In Switzerland it is widespread in settlements and warm lowland areas, but absent from the main Alpine ridge. Swiss Red List: Least Concern (LC).