Like many other riodinids, the caterpillars are myrmecophilous and have tentacle nectary organs that exude a fluid similar to that produced by the host plant Calathea ovandensis.

This mutualistic relationship allows ants to harvest the exudate, and in return provide protection in the form of soil shelters for larvae.

As in all butterflies, E. elvina are holometabolous and have four distinct development stages: egg, larva, pupa and adult.

[2][3] The females lay the eggs on the upper surface of leaves, leaf petioles, or on the inflorescence of neotropical plants such as Calathea ovandensis.

Characteristic of myrmecophilous riodinids, all the larval stages possess tentacle nectary organ (TNO) on the eighth abdominal segment.

The foremost segment of the thorax is covered by a protective black shield into which the head of the caterpillar is partially retractable.

When freshly molted, the caterpillar is pale-cream in color, but it gradually changes to a brownish-yellow, and the dorsal bands turn maroon as the stage progresses.

[2] The body color of the fourth instar varies from a light to dark avocado green.

This instar possesses a similarly bicolored prothoracic shield and reduced dorsal setae.

[2] The pupa is bright green, matching the colors of the young leaves of the host plant on which it is found.

The proboscis eventually extends completely and changes from dark green to brown like the rest of the pupa.

[7] The long proboscis of the adult does not touch the stigma or the pollen of the plant while feeding on C. ovandensis.

The tentacle nectary organ (TNO) found that the eighth abdominal segment of the larval stages plays a special role in this interaction.

The later instars of the caterpillar position themselves in the inflorescence such that the TNO is presented to the ants at roughly the same level of the nectaries of the flower.

The caterpillar was observed producing 12–15 pulses of sound per second when walking and foraging, either when alone or when accompanied by E. ruidum ants.