Photo: Kjell Magne Olsen / CC BY 4.0

Bombus ruderarius

Red-shanked Carder Bee

A medium-sized carder bumblebee (14–17 mm) with a black body, a bright orange-red tail, and distinctive orange-red hairs on the hind leg pollen basket (corbicula), which distinguishes it from the similar Bombus lapidarius which has black corbicular hairs. The face and tongue are relatively long. It nests on or just below ground level in grass tussocks or moss, carding together nesting material. Colonies have 50–100 workers. It forages on clovers, vetches, dead-nettles, and other deep flowers. In Switzerland it occurs in flower-rich meadows, grasslands, and gardens from lowlands to montane elevations, but has declined due to agricultural intensification. A nest was documented near Splügen (Grisons) at 1750 m. Swiss Red List: Least Concern (LC).