Oligolectic: Salix (Salicaceae). Sixteen pollen loads analysed by Westrich & Schmidt (1987) from various sites in southern Germany, contained only Salix pollen. In the field these authors also observed females foraging for pollen exclusively from Salix, including S. purpurea and S. alba. Westrich (1989) also lists Salix caprea, Salix aurita, Salix pentandra and Salix nigricans.
Pekkarinen (1998) lists Salix (Salicaceae) as the pollen source in Finland.
Tomozei & Radchenko (2015), citing others, state that the species is considered oligolectic and will forage specifically on Salicaceae species (Salix purpurea, Salix alba, Salix caprea, Salix aurita, Salix pentandra, Salix nigricans), although it was found also on Apiaceae (Heracleum sibiricum); Asteraceae (Taraxacum officinale); Caryophyllaceae (Dianthus carthusianorum, Silene otites); Poaceae (Koeleria glauca); Ranunculaceae and Rosaceae (Cerasus, Crataegus, Malus, Spiraea).