Nacaduba calauria, the dark Ceylon six-lineblue, is a species of lycaenid butterfly found in Indomalayan realm. and New Guinea.
Subspecies N. c. calauria New Guinea Sula, Maluku New Britain N. c. malayica Corbet, 1938 Peninsular Malaya, Singapore, Sumatra, Borneo N. c. cypria Toxopeus, 1929 Java N. c. evansi Toxopeus, 1927 Ceylon References