A univoltine species: March or April to May (late June in Finland). There are even records from August, September and October (Söderman & Leinonen, 2003). In some favourable years, the earliest specimens can be on the wing from February
Parasites and Predators: The bees Nomada lathburiana, Sphecodes gibbus and S. albilabris are cited as a cleptoparasites of this species (Söderman & Leinonen, 2003).
In northern Germany and Denmark it is also attacked by Stylops muelleri; also in Denmark possibly S. krygeri (both reported by Kinzelbach, 1971b).
Smit et al (2018) report that Andrena vaga is a proven host of both Myopa hirsuta (Jentzsch 2009) and M. testacea (Erteld 1998, Fellendorf et al. 2004, De Meijere 1912)
Stubbs (2001) citing Mueller (1944), suggests that the bee-fly Bombylius discolor may be an inquiline in nests of this species.
Tomozei & Radchenko (2015) state that Andrena vaga is host to the cleptoparasite Nomada lathburiana, and of the Coleoptera Meloe decorus, Meloe proscarabaeus and Meloe violacea.