Adults are known to feed on a variety of nectar plants.
The genus Heliconius is broken into two parts: Helico = Helix and nous = reason and knowledge, as opposed to sense perception. Ismenius comes from Ismenos, a Greek river god.
The Ismenius Longwing prefers the middlestory of sunny tall forests.
Females mate with multiple males and lay one or two eggs under the younger leaves of a host plant. When they hatch, the larvae feed on the host plant until they form pupae. The larvae prefer to feed in solitude as to avoid easy detection by predators.
There are multiple generations each year which makes it possible to find the adults year round.
Like all Heliconius, the Ismenius Longwings are long lived individuals, lasting over two months in the adult stage. At night, adults will congregate in large groups, usually at the forest edge, on the tendrils of host plants and trees.