Oligolectic on Echium (Boraginaceae) (Amiet et al., 2004; Banaszak and Romasenko, 2001; Stanisavljević, 2000; Benoist, 1931; Gogala, 1999; Westrich, 1989; A. Müller, unpublished, based on 3 pollen samples from 2 different localities and on field observations).