Polylectic. Material from the Russian Far East was all caught at flowers of Veronica incana. (Plantaginaceae) (Pesenko, Banaszak et al., 2000). Müller (2018) regards the species as Polylectic (13 plant families).
Ebmer (1984) lists Euphrasia rostokoviana, Veronica spicata (Plantaginaceae), Silene rupestris (Caryophyllaceae), Thymus serpyllium (Lamiaceae) and Phyteuma scheuchzeri (Campanulaceae), Hieracium (Asteraceae).
Westrich (1989) states that the species is polylectic, with pollen foraging from species of Asteraceae, Caryophyllaceae and Lamiaceae.
Müller (2018) lists the following forage sources in the Alps: Crassulaceae; Euphrasia-type (Orobanchaceae); Lamiaceae (Nepetoideae); Helianthemum (Cistaceae); Asteraceae (Cichorioideae, Carduoideae, Asteroideae); Caryophyllaceae; Gentianaceae; Potentilla-type (Rosaceae); Soldanella (Primulaceae); Saxifraga (Saxifragaceae); Salix (Salicaceae); Fabaceae; Campanulaceae
Bossert (2014) reports foraging at Leontodon hispidus (Asteraceae) in the Austrian Tyrol