Broadly oligolectic on Asteraceae. Osmia spinulosa is the only species of Osmia (Hoplosmia) known to regularly collect pollen on representatives of all three main subfamilies of the Asteraceae, i.e. Asteroideae, Carduoideae and Cichorioideae (Müller, 2018)
Flowers visited in the UK (Else & Edwards, 2018): Ranunculus (Ranunculaceae); Jacobaea, Pulicaria dysenterica, Cirsium vulgare, Centaurea, Cichorium intybus, Hieracium and Taraxacum (Asteraceae).The pollen load of a Bedfordshire female was analysed by V.H. Chambers and found to consist entirely of Leontodon hispidus (Asteraceae) (taken from Chambers pollen record cards).
Banaszak & Romasenko (1989), copied by Stanisavljević (2000), list the following forage sources: Hieracium, Centaurea, Inula, Anthemis, Carduus, Cichorium, Tragopogon (Asteraceae).
Stratan (1998), lists the following forage sources in Moldova: Grindelia sqarrosa, Xeranthemum annuum, Carduus sp. (Asteraceae); Teucrium polium, Teucrium chamaedrys (Lamiaceae).
Ivanov et al. (2005) state that the species is oligolectic on Asteraceae.
Müller et al (2006) additionally list Buphthalmum salicifolium (Asteraceae) and Matache & Ban (2006) report collecting specimens from unspecified Apiaceae.
Müller (2018) lists the following pollen sources: Anthemis, Aster, Buphthalmum, Inula, Senecio, Carduus, Centaurea, Cirsium, Cichorium, Crepis, Hieracium, Leontodon, Picris, Tragopogon (Asteraceae).