As this is a cleptoparasitic species, all flower visits will be for nectar only.
Flowers visited: The first brood flies to Brassica (Brassicaceae); Salix alba, Salix repens (Salicaceae); Euphorbia (Euphorbiaceae); Armeria maritima (Plumbaginaceae); and Bellis perennis (Asteraceae); the second brood visits Rubus (Rosaceae); Senecio, Solidago and Cirsium arvense (Asteraceae).
Pawlikowski & Kruszynski (1997) list Potentilla arenaria (Boraginaceae) as a nectar source in Poland.
Smit (2004), citing others, lists the following nectar sources: Salix sp. (Salicaceae); Veronica (Scrophulariaceae); Ranunculus ficaria (Ranunculaceae); Taraxacum officinale (Asteraceae).