A univoltine species flying in Scotland from May (exceptionally late April) to early July (Else & Edwards, 2018). Amiet et al. (2004) give a flight period in Switzerland from the mid-March to early August.
Parasites and predators It is probable that the chrysidid wasp Chrysura hirsuta is a cleptoparasite in Scottish nests, as it is in Germany (F.K. Stöckhert, 1933). This wasp has been collected in a Scottish woodland site where Osmia uncinata occurred, but direct evidence that this cleptoparasitism exists in Britain has yet to be been obtained.
Banaszak & Romasenko (1989) additionally cite Sapyga similis (Sapygidae) as a parasite.