Callistium is a butterfly genus in the family Riodinidae. There are two species both resident in the Neotropics.
Species list Callistium cleadas (Hewitson, 1866) Guyane, Guyana, Amazon biome Callistium maculosa (Bates, 1868) Brazil (Amazonas)
Sources
Callistium at Markku Savela's website on Lepidoptera