Nesting sites of Osmia pilicornis in dead fallen branches (see Table 2): 3–4 Nesting site 1 with nests 1 and 2 in a branch of Fraxinus excelsior 5–6 Nesting site 2 with nest 3 in a branch of Picea abies 7–9 Nesting site 3 with nests 4 and 5 in a branch of Salix spec. 10–11 Nesting site 4 with nest 6 in a branch of Corylus avellana.

 
 
  Part of: Prosi R, Wiesbauer H, Müller A (2016) Distribution, biology and habitat of the rare European osmiine bee species Osmia (Melanosmia) pilicornis (Hymenoptera, Megachilidae, Osmiini). Journal of Hymenoptera Research 52: 1-36. https://doi.org/10.3897/jhr.52.10441