Praz (2017) reports that Megachile pilidens is a Polylectic species, but with a strong preference for Fabaceae pollen.
Banaszak & Romasenko (1989), copied by Stanisavljević (2000), list the following forage sources: Medicago, Onobrychis, Vicia, Coronilla, Lotus (Fabaceae); Helianthus, Inula, Cirsium (Asteraceae).
Peeters, Raemakers, vd Nieuwegiessen & Kuper (2007) show a photograph of the species visiting flowers of Medicago sativa (Fabaceae) in Switzerland. The same authors list these forage plants: Ononis repens, Ononis spinosa, Medicago falcata, Lotus corniculatus (Fabaceae); Scabiosa columbaria (Dipsacaceae); Origanum vulgare (Lamiaceae); Achillea millefolium (Asteraceae).
Flower records from specimen and observation data are listed as: Eryngium campestre (Apiaceae); Cardopatium corymbosum, Centaurea orphanidea ssp. orphanidea, Chondrilla juncea, Pallenis spinosa, Phagnalon graecum (Asteraceae); Heliotropium spp. (Boraginaceae);Ecballium elaterium (Cucurbitaceae); Ononis spinosa (Fabaceae); Hypericum triquetrifolium (Guttiferae); Ballota acetabulosa, Coridothymus capitatus (Lamiaceae); Convolvulus cantabrica (Convolvulaceae); Delphinium peregrinum (Ranunculaceae); Urginea maritima (Liliaceae); Verbascum undulatum (Plantaginaceae); Vitex agnus-castus (Verbenaceae) (Petanidou, 1991)
Pittioni et al (Accessed, 2017) report female visitation to Lotus corniculatus (Fabaceae). In Cyprus, the species is very active at flowers of Dittrichia viscosa (Asteraceae) in October (Roberts, 2017, pers obs).
Gogala (2013) reports that the species visits mainly Fabaceae, Lamiaceae, Dipsacaceae and Asteraceae.
Herrera (in litt. 2017) states that Megachile pilidens.is the principal poliniator of Drimia (=Urginea)maritima (Asparagaceae) in the Sierra de Cazorla, Spain