Broadly oligolectic. Pollen sources not known but believed to be various species in the family Asteraceae (eg Ivanov et al., 2005)
In France, Correia (1976) analysed the provision in her trap nests and found that this consisted of pollen collected from Senecio, Arctium, Cirsium, Crepis and Inula (Asteraceae) Käpylä (1978), in Finland, established that the preferred forage plants were Tripleurospermum inodorum and Leontodon autumnalis (Asteraceae.) Pollen was occasionally collected from Cirsium arvense, and more rarely Centaurea jacea (Asteraceae)
Else & Edwards (2018) note that British females have been observed visiting Jacobaea vulgaris, Pulicaria dysenterica and Sonchus arvensis (Asteraceae) “Thistles” are also visited (Morice, 1900). Of the non-Asteraceae flowers, Käpylä (1978) reports that in Finland, Potentilla (Rosaceae) is the most often visited plant, being especially favoured by males. The latter otherwise visit roughly the same plant species as females. Also in Finland, Elfving (1968) lists 31 plant species visited by Heriades truncorum, but there is no indication which species are exploited for pollen and which purely for nectar.
Pekkarinen (1998) lists plants in the following genera of Asteraceae as pollen sources in Finland: Achillea, Arnica, Aster, Anthemis, Bidens, Calendula, Centaurea, Cirsium, Crepis, Erigeron, Hieracium, Inula, Lapsana, Leontodon, Leucanthemum, Matricaria, Taraxacum and Tripleurospermum.
Mavromoustakis (1960) lists Pallenis spinosa (Asteraceae) as a forage source on Rhodos and Praz et al (2008) list Tanacetum vulgare and Buphthalmum salicifolium (Asteraceae) as pollen sources in Switzerland
Mavromoustakis (1948; 1952) reports visitation to Dittrichia (=Inula) viscosa, Inula crithmoides, Pulicaria dysenterica (Asteraceae) in Cyprus