They suck nectar of the preferred blue violet flowers, such as on field scabious (Knautia arvensis), Dove Pincushion Flower (Scabiosa columbaria), meadow knapweed (Centaurea jacea), panicle knapweed (Centaurea stoebe), creeping thistle (Cirsium arvense), Bulbous thistle (Cirsium tuberosum) and ring thistle (Carduus).