They feed on the nectar of various flowers, including Salvia columbariae, Asclepias cordifolia, Ribes aureum, Dichelostemma capitatum, Clarkia, Vicia, Cirsium and Stachys species.
Hughes' powerfully imagined dragon Vicia-Heinox with its two bickering heads has set a pattern for the portrayal of similar creatures in other media, including the animated film Quest for Camelot (1998) and the public television children's program Dragon Tales (1999 onward).
The larvae feed on various low-growing plants, including Vicia, Lotus, Hippocrepis and Teucrium species.