"E. core" is a glossy-black, medium-sized butterfly with rows of white spots on the margins of its wings. "E. core" is a slow, steady flier. Due to its unpalatability it is usually observed gliding through the air with a minimum of effort. As caterpillars, this species sequesters toxins from its food plant which are passed on from larva to pupa to the adult. While feeding, it is a very bold butterfly, taking a long time at each bunch of flowers. It can also be found mud-puddling with others of its species and often in mixed groups. The males of this species visit plants like "Crotalaria" and "Heliotropium" to replenish pheromone stocks which are used to attract a female during courtship.