A univoltine species; end of May to mid or late September (Edwards & Else, 2018; Stanisavljević, 2000; Amiet, 2004).
Parasites and predators: Specimens of the chalcid wasp Pteromalus apum have been reared from a cocoon of this bee which had been removed from a nest collected in Hampshire(pers. obs).
Stelis phaeoptera is listed as a cleptoparasite in Germany and the Netherlands (Gehrs, 1902 ; van der Zanden, 1982). Other aculeate cleptoparasites, not found in Britain, have been reported in mainland Europe (see F.K. Stöckhert, 1933).
Banaszak & Romasenko (1989) list Stelis odontopyga (Megachilinae) and Chrysis trimaculata and Chrysis cuprea as parasites.