Oligolectic on Asteraceae with a preference for Carduoideae; species of the Cichorioideae are exploited as pollen sources as well (based on 29 pollen loads from 23 different localities in Greece, Israel, Jordan and Syria and on field observations). Of the 29 pollen loads, 27 consisted exclusively of pollen of Carduoideae (Centaurea and/or thistles), while the other two loads also contained pollen of Asteroideae (n = 1) and Cichorioideae (n = 1)(Müller, 2018). This suggests that O. spinigera exhibits a strong preference for Carduoideae but occasionally also exploits flowers of Asteroideae and Cichorioideae.
Müller (2018) additionally cites the following flower records: Pallenis spinosa, Centaurea crocodylium, Centaurea hyalolepis, Centaurea iberica, Centaurea pallescens, Centaurea procurrens, Centaurea spinosa, Glebionis coronaria, Silybum marianum (Asteraceae).