From a report in Science News:
Rhainer Guillermo Ferreira was so jolted by a scanning electron microscope image showing what looked like skinny, branching tracheal tubes in a morpho wing that he called in another entomologist for a second opinion. Guillermo Ferreira, then at Kiel University in Germany, showed the image to a colleague who also was “shocked,” he remembers. A third entomologist was called in. Shock all around...Here's a scanning EM of the wing:
In the tough inner layers, male Z. lanei wings form nanoscale spheres sandwiched between blankets of black pigment–filled nanolayers. This setup can enhance reflections of blue light and muddle other wavelengths.
The article is here.