Rustic

Naming

* ''C. e. lotis'' is synonymised with the nominated subspecies. Its wingspan ranges from 45 to 55 mm.
⤷  Var. ''nicobarica'' Felder generally, but not always, has the interspace between the postdiscal and subterminal transverse series of lunules on the upperside of the hindwing paler than the ground colour of the wings.
⤷  Subspecies ''andamanica'' Moore has the upperside ground colour a very dark ochraceous brown, much darker than in ''erymanthis''. Markings on the upper and underside are similar, but on the upperside the spots on the discal band on the forewing are larger, especially the lowest spot. On the hindwing the upper three spots of the discal series are conspicuously larger. On the underside the ground colour is darker and the markings are more clearly defined than in the typical form.
⤷  Subspecies ''placida'', of southern India was previously considered a full species. The upperside differs as the forewing discal band is distinctly darker yellow. Its inner and outer margins are much less sinuous and irregular and the black line defining the inner margin is more slender. The spots on the band in interspaces 1,2 and 3 are much smaller, especially the spot in interspace 1, which is no larger than the others and is diffuse and ill defined. The subapical yellow spots on the black area are usually absent or, if present, are diffuse and indistinct. On the hindwing, the outer subbasal line, with its outer border of pale spots, is generally more clearly defined than in ''erymanthis''. Both forewings and hindwings are shaded at the base with olivaceous brown. Markings on the underside are similar to those in ''erymanthis'' but are more heavily defined.* ''Cupha erymanthis maja'', Fruhstorfer – Sahyadri rustic
⤷  ''Cupha erymanthis lotis'', Sulzer – Himalayan rustic
⤷  ''Cupha erymanthis andamanica'', Moore – Andaman rustic
⤷  ''Cupha erymanthis nicobarica'', Felder – Nicobar rustic

Habitat

The rustic caterpillars feed mainly on Flacourtiaceae species, for example ''Flacourtia montana'', ''F. ramontchii'', ''F. rukam'', ''Xylosma racemosa'' and ''Scolopia'' species. They also eat plants such as ''Glochidion eriocarpum'' and ''Lepisanthes rubiginosum''.

Adult butterflies occasionally visit carrion to drink the fluids. They seem to favour carcasses lying in exposed, sunny areas over those which are in the shade.