Scanning electron microscope (SEM) view moving over the edges of the wings of a glasswing butterfly (Greta oto). Glasswing butterflies are so named as their wings are only partially covered in coloured scales, with large areas scale-free and transparent like the wings of other insects. This is clearly seen under electron microscopy: the outer part of the wing and the wing veins are covered in tiny overlapping scales, while the inner parts of the wing are smooth. This butterfly is native to Central America.