The family Nymphalidae is the largest family in the order Lepidoptera. Known as the brush footed butterflies, this family has reduced forelegs used only as sensory organs. They balance themselves on their prominent hind four legs outstretched for stability.
The subfamily Danainae, the milkweed butterflies, can be recognized by their thick black cross veins and dark outer boarders. Many like the Greta Oto and its cousin the Danaus Plexippus monarch butterfly have bright orange accent colors. Members of this subfamily also have long black antenna and white dots speckled across the head and thorax.
The genus Greta was named in 1934 by the well know English entomologist Francis Hemming. The genus is known for their distinctive trait of transparent wings.