Photo: Daniel Ballmer / CC BY-SA 4.0

Hoplitis adunca

Viper's Bugloss Mason Bee

A medium-sized mason bee (8–13 mm) with a black body, white ventral scopa, and narrow white hair bands on the tergites. Males are initially densely rust-red haired, fading to grey. It is strictly oligolectic on Echium (viper's bugloss, Boraginaceae), collecting the distinctive grey-blue pollen exclusively from these plants. It nests in pre-existing cavities such as beetle burrows in dead wood, hollow stems, and abandoned nests of other bees, as well as bee hotels, sealing cells with a hard mortar of sand and small pebbles mixed with saliva. In Switzerland it occurs in warm, dry habitats with Echium stands, such as vineyards, quarries, railway embankments, and ruderal areas up to 2100 m in the Alps. Swiss Red List: Least Concern (LC).