Some authors regard this as a polylectic species, but showing a marked preference for Carduus, Cirsium and Centaurea (Asteraceae) (Banaszak & Romasenko, 1989; Stanisavljević, 2000). Praz, (2017), however regards he species as oligolectic on Asteraceae, with a preference for Carduoideae (C. Praz, unpublished data).
Mavromoustakis (1960) lists the following forage sources in Rhodes: Centaurea (Asteraceae); Vitex agnus-castus (Lamiaceae). Mavromoustakis (1948; 1951; 1952; 1954) also adds Scolymus hispanicus, Cardopatium (=Broteroa) corymbosum, Centaurea cilicica, Echinops spinosus, Carlina lanata, Centaurea hyalolepis, Onopordum insigne (Asteraceae); Heliotropium europeum (Boraginaceae); Limonium (=Statice) virgata (Plumbaginaceae); Teucrium polium micropodioides, Marrubium vulgare apolum, Vitex agnus-castus (Lamiaceae) as forage plants for this species (listed under Megachile sericans cyprica Cockerell).
Data from specimens and observations show that the species will visit a wide range of forage sources, presumably these include nectaring visits as well as pollen collecting: Eryngium creticum (Apiaceae); Carlina curetum, Carthamus tenuis, Centarurea iberica, Centaurea hispanica, Centaurea orphanidea ssp orphanidea, Centaurea solstitialis, Echinops adenocaulos, Echinops microcephalus, Notobasis syriaca, (Asteraceae); Teucrium creticum, Ballota acetabulosa, Satureja thymbra, Thymus capitatus (Lamiaceae); Echium angustifolium, Echium judaeum (Boraginaceae); Plantago sp. (Plantaginaceae); Nigella arvensis (Ranunculaceae).
Ortiz-Sanchez et al. (2012) report visitation to Cynara cardunculus (Asteraceae) in Portugal.