Nesting behaviour of Osmia pilicornis (see Table 2): 15–16 Females of nests 1 and 4 tunneling out burrows in dead branches 17–18 Females of nests 2 and 4 transporting small leaf fragments of Fragaria vesca to build brood cell partitions and nest plug 19 Female harvesting nest-building material on a leaf of Fragaria vesca 20 Female of nest 4 returning from a foraging flight with pollen-filled metasomal scopa.