Around 3700 butterfly species live in Germany. About 95 percent of them belong to the moths. They have a reputation for being much more drab in color than their daytime relatives. But this first impression is deceptive, as a study by Meng Li from the University of Lund and Co. in the “Journal of the Royal Society Interface” shows: Under the right light, owl, moth and buffalo moths present themselves in iridescent colors.
The working group examined 82 animals from 26 species and photographed their wing scales using a special technique that captures certain wavelengths of light that are invisible to the human eye. It turned out that the wings actually glow in the infrared range and show a wide variety of colors, while in sunlight they simply appear brown or gray.
Different species also reflect light in different patterns, so each species has a specific signal. These patterns helped the team determine the structure of the scales on the moth’s wings. The black and white colored forms of the Peppered Moth (Biston betularia) about also differ in the structure of their wing scales. Until now, it was assumed that only the content of melanin determines the color of the wings.
Li and Co now hope that the different infrared signatures could help to identify moths. After all, the diversity of moths has so far only been insufficiently recorded. However, there are reasons why they appear rather monotonous to the human eye. During the day, the moths have to hide from predators: muted tones seem helpful here.