Hecale Longwing Butterfly, Heliconius hecale, a.k.a. Tiger longwing. RANGE: South America. The longwing butterflies have unusually long lifespans and high fecundity rates, which largely result from their augmented diet. Instead of surviving on food stores from the larval stage or solely sipping flower nectar, adult longwing butterflies are vivid pollen eaters. This trait makes them eminently suitable for butterfly farming and butterfly gardening. Also, adult longwings may live for several months, much longer than most butterflies. The longwing butterflies are also known as Heliconians. They are brightly colored with long forewings. Once placed in their own family, they are now considered closely related to the fritillaries. The larvae of most longwings feed on passion vines, and this host plant imparts noxious chemicals to the larvae which are carried over to the adult butterflies. Predators find these chemicals distasteful and avoid eating the butterflies.