Hoplitis robusta. 1) Female collecting pollen and nectar on Potentilla erecta. 2) Head of female. 3) Nesting habitat in the Calfeisen valley near St. Martin (St Gallen). 4) Dead fallen spruce (Picea abies) with nesting branch marked with red arrow. 5) Nesting branch with nest entrances marked with red arrows.

 
 
  Part of: Müller A, Richter H (2018) Dual function of Potentilla (Rosaceae) in the life history of the rare boreoalpine osmiine bee Hoplitis (Formicapis) robusta (Hymenoptera, Megachilidae). Alpine Entomology 2: 139-147. https://doi.org/10.3897/alpento.2.30158