Univoltine: flying from April to mid June, rarely mid July and August. In Czechoslovakia the species is bivoltine, the first brood appearing in April and May, the second in July and August. The summer brood is much rarer than the earlier one and is not recorded from many localities (Kocourek, 1966). In the Netherlands it may also be bivoltine (Vegter, 1985), the spring brood flying in April and May, the summer one in June and July (the latter brood occurring in only small numbers). Westrich (1989) considers the species to be possibly bivoltine in south-west Germany. It is thus possible that apparently freshly emerged British specimens collected in July may represent a small, partial second brood.
Parasites and predators: Host of a number of cleptoparasitic bee species. Nomada alboguttata, Sphecodes pellucidus and S. reticulatus (Westrich, 1989).