RAMOS MEJIA, ARGENTINA
The Madagascan sunset moth’s wings are covered with iridescent scales that appear to glimmer in the light. Unlike most moth species, this one is active during the day. Its colours warn predators that it is poisonous and not worth their trouble.
The moth’s scales, seen here at 20x magnification, are essentially modified hairs. The colour comes not from pigments, but from two clever ways in which the scales manipulate light.
First, the scales are made of alternating layers of cuticle material and air. Light waves reflected off these layers interact with each other, and the number of layers in the scales varies, so different wavelengths are reflected more strongly at different points, creating these awesome colours.
Second, the curved shape of the scales causes light to be reflected from scale to scale, enhancing the overall effect. NIKON SMALL WORLD 2018