Polylectic, but known pollen sources recorded in Britain apparently limited to Lotus corniculatus and an Ononis species (Fabaceae)(Else & Edwards, 2018).
In Germany, the bee visits: Buphthalmum salicifolium, Inula hirta, Carduus acanthoides, Onopordum acanthium (Asteraceae); Echium vulgare (Boraginaceae); Heliantemum nummularium (Cistaceae); Hippocrepis comosa, Lotus corniculatus, Vicia sepium, Lathyrus tuberosus, Lathyrus pratensis, Onobrychis viciifolia, Trifolium pratense, Trifolium montanum, Trifoloium repens, Ononis spinosa, Ononis repens, Medicago sativa, Melilotus alba, Lupinus polyphyllos, Chamaespartium sagittale, Genista tinctoria, Tetragonolobus maritimus (Fabaceae); Salvia pratensis, Lamium purpureum, Ajuga reptans, Glechoma hederacea, Teucrium montanum, Stachys recta (Lamiaceae) and Plantago media (Plantaginaceae)(Westrich, 1989).
In UK the species has a marked preference for Fabaceae, including Lotus corniculatus, Anthyllis vulneraria and Hippocrepis comosa. Other flowers visited include Glaucium flavum (Papaveraceae); Viola (Violaceae); Rubus, Rosa pimpinellifolia (Rosaceae); Salix repens (Salicaceae); Armeria maritima (Plumbaginaceae); Glechoma hederacea (Lamiaceae), Taraxacum (Asteraceae); and Orchis (Orchidaceae)(Else & Edwards, 2018).
Baldock et al (in prep.) report visitation to Teucrium sp. (Lamiaceae) and Scabiosa (Dipsacaceae) in the Balearic Islands (Spain)
Fateryga (2017) reports visitation to Hedysarum tauricum (Fabaceae) in the Krasnodar region of the North Caucasus (Russia).
Stratan (1998), lists the following forage sources in Moldova: Coronilla varia (Fabaceae); Ballota nigra (Lamiaceae).
Banaszak & Romasenko (1989), later copied by Stanisavljević (2000), state that the species, whilst being polylectic, shows a marked preference for Vicia, Coronilla, Amorpha, Melilotus, Hippocrepis (Fabaceae); and Salvia, Ajuga, Leonurus, Stachys, Lamium, Glechoma (Lamiaceae). Monsevicius (2004) lists the following forage plants in Lithuania: Astragalus arenarius, Lathyrus maritimus (Fabaceae); Sedum acre (Crassulaceae); Echium vulgare (Boraginaceae); Hieracium pilosella (Asteraceae).
Mueller summarising the known literature (http://blogs.ethz.ch/osmiini/palaearctic-species/osmia/helicosmia/) states that the species is polylectic with a preference for Fabaceae (e.g. Chameaspartium, Genista, Hippocrepis, Lathyrus, Lotus, Lupinus, Medicago, Melilotus, Onobrychis, Ononis, Tetragonolobus, Trifolium, Vicia) and Lamiaceae (e.g. Ajuga, Glechoma, Lamium, Salvia, Stachys, Teucrium); other pollen sources include Plantaginaceae (Antirrhineae), Cistaceae (e.g. Helianthemum), Boraginaceae (e.g. Echium) and Polygalaceae (Westrich, 1989; Müller, 1996b; A. Müller, unpublished, based on 45 pollen samples from 34 different localities and on field observations). Westrich (1989) lists Asteraceae and Plantago (Plantaginaceae) as additional pollen hosts. The females are equipped with a specialized pilosity on the clypeus composed of curved bristles, which are used to comb pollen from the nototribic anthers of Lamiaceae and Plantaginaceae (Antirrhineae) (Müller, 1996b