Polylectic. Müller & Kuhlmann (2008) list Salix (Salicaceae), Cichorioideae (Asteraceae), Aceraceae, Fabaceae, Rosaceae, Ericaceae, Resedaceae, Rhamnaceae, Brassicaceae, Grossulariaceae and Cistaceae based on 44 pollen loads from 27 different localities.
The species has been observed collecting pollen of Brassica (Brassicaceae) (Gogala, 1999).
The species shows a clear preference for Salix (Salicaceae) in GB.
In Britain, reported as monolectic on Salix repens (O'Toole, 1974), visiting other species in this genus only for nectar. However, at a coastal site on the Wirral peninsula (Merseyside), in April 1996, females of this species were foraging exclusively at Salix cinerea, there being no S. repens present (C. Clee, pers. comm.).
In Finland it is reported to be oligolectic, visiting Salix caprea (Salicaceae). Vereecken (in litt.) reports foraging at the same species in south western France. Pekkarinen (1998) lists Salix (Salicaceae) as the pollen source in Finland.
Ornosa & Ortiz-Sánchez (2004), citing other authors, list Salicaceae, Ranunculaceae, Brassicaceae, Rosaceae, Asteraceae and Liliaceae.
Bischoff et al (2003) state that 40% of all cells analysed contain more than 20% non-Salix pollen. Other pollen sources listed by Bischoff include Sorbus aucuparia, Prunus padus, Prunus laurocerasus, Pyrus sp., Malus sp. (Rosaceae); Quercus sp. (Fagaceae); Sambucus nigra (Caprifoliaceae); Ranunculus sp. (Ranunculaceae); Euonymus europaeus (Celastraceae); Acer sp. (Aceraceae), Ilex aquifolium (Aquifoliaceae). It also visits Pistacia lentiscus () in Turkey and in Italy it has been observed foraging exclusively on Fabaceae.
Vereecken (2004) has shown that males of C. cunicularius are the exclusive pollinator of the sexually deceptive orchids Ophrys exaltata and Ophrys arachntiiformis (Orchidaceae).