This species is cleptoparasitic so all flower visits are for nectar.
Celary (1990) lists Thymus sp. Betonica officinalis (Lamiaceae); Melilotus (Fabaceae) as nectar sources in Poland.
Mavromoustakis (1948, 1951; 1952) reports nectar foraging at Heliotropium europeum (Boraginaceae); Vitex agnus-castus, Teucrium polium micropodioides (Lamiaceae); Centaurea cilicica (Asteraceae); Limonium (=Statice) sp. (Plumbaginaceae);.