Greta Oto, known simply as the butterfly wings of glass, is characterized by a fabric which occupies 3/4 of its wing surface that does not have pigment, unlike the common butterflies.
The transparency that results is vital to the survival of the insect, as it makes more complicated his pursuit by predators. Under certain conditions, the wings of this butterfly spread mainly in Central America, have reflective power. Hence its nickname Spanish, "Having fulfilled", which in Italian means "little mirrors."