Strongly oligolectic on Echium species (Boraginaceae). Westrich (1989) lists: Echium vulgare, Echium italicum, Echium plantagineum. (Amiet et al., 2004; Banaszak and Romasenko, 2001; Gogala, 1999; Westrich, 1989; Stanisavljević, 2000). A. Müller, unpublished, based on 29 pollen samples from 19 different localities and on field observations). (Westrich 1989, Gogala 1999, Banaszak and Romasenko 2001, Amiet et al. 2004, Sedivy et al. 2013a).
Ivanov et al (2005) state that the species is monolectic on Echium (Boraginaceae) which is clearly an error of understanding.