As this is a cleptoparasitic species, all flower visits will be for nectar only.
Westrich (1989) lists the following nectar sources: Jasione montana (Campanulaceae); Sedum acre (Crassulaceae); Achillea millefolium, Tanacetum vulgare, Inula, Hieracium (Asteraceae). In Finland found visiting Sedum acre (Crassulaceae)(Elfving 1968)