H. erato is relatively common in gardens, clearings and other open areas, where it flies side by side with its co-mimic H. melpomene. H. erato and H. melpomene also may roost together at night. At La Selva these species can usually be found in the successional plots and in other open second growth areas. H. erato belongs to the "erato-charithonia" species group ("group I"), which primarily feed as larvae on Passiflora subgenus Decaloba. At La Selva H. erato lays her eggs on P. biflora, usually placing the eggs on or in the shoot tips where they are more hidden from hymenopteran egg parasitoids. The local color form of H. erato is called petiverana (Range: Mexico to Panama). The species takes on radically different color forms across its range; however, the underlying species biology and natural history are much more conservative. Overall range: Mexico to the Amazon Basin.

Occasionally, H. erato feeds on a few other Decaloba species, including P. auriculata and P. megacoriacea. It grows poorly or not at all on P. costaricensis. Like many others in the Heliconius species group I, they die when fed subgenus Passiflora, including P. ambigua and P. oerstedii.