Wikipedia
Pierella
Pierella is a butterfly genus from the subfamily Satyrinae in the family Nymphalidae found from Mexico through Central America to South America. The species of Pierella have larger hindwings than forewings, unique among butterflies. The oval green flash on the forewing is also unique. It is caused by diffraction, the wing scales forming a diffraction grating.
Their caterpillars have been found on the host plants Heliconia and Calathea.