Nesting biology of Hoplitis tuberculata: 1 Female leaving her nest in a preexisting burrow in dead wood 2 Female transporting leaf pulp in her mandibles 3 Female collecting leaf pulp from the sepals of Potentilla erecta 4–5 Dead tree stumps with beetle burrows used as nesting sites (Sedrun, Grisons, Switzerland) 6–8 Sealed nests with outermost wall of nest plug with pebbles and earth crumbs embedded in the leaf pulp matrix 9 Sealed nest with outermost wall of nest plug consisting of leaf pulp only.