A univoltine species with an extended flight period. Females from early April to at least August, males from late August to mid October. In the more southerly parts of the range (eg Spain and in the High Atlas mountains of Morocco), the males can be found flying with the females in early spring,
Label data from a few Spanish specimens shows that females are active from (at least) March to June, and males are active in March (Ortiz-Sanchez & Pauly, 2017).
Parasites: Sphecodes spinulosus has been reported as a cleptoparasite of this species (R.C.L. Perkins, 1923, 1924). Hallett (1928) observed specimens of this Sphecodes and gigantic females of S. monilicornis at the burrows of the Lasioglossum. Rarely stylopised, the parasite being Halictoxenus arnoldi (R.C.L. Perkins, 1891b, 1918c, 1923).