The tree-like structures in this scanning electron microscope image of a cross section of a butterfly wing are on the undersides of the Morpho's wing scale ridges. These microribs reflect light to create iridescent colors.
The Blue Morpho is common in Central and South America and known for its bright blue wings. However, these iridescent colors are created not by pigments in the wing tissues but instead by the way light interacts with nanometer-sized structures on the Morpho's wing scales. This effect is being studied as a model in the development of new fabrics, dye-free paints, and anti-counterfeit technologies for currency.
• SIZE: The microribs on the wing scale ridges are each about 400 nm long.
• IMAGING TOOL: Scanning electron microscope