There is a nocturnal moth that not only has conspicuous dots on the hindwings, but can also quietly attract the opposite sex in the dark through changes in the microstructure of the forewings. In a study published in the September 2019 issue of the journal Contemporary Biology, the scientists demonstrated their findings: Looking at spots on the forewings of male nocturnal moths from a specific perspective, there are three different changes in darkness and size, while the forewings of female nocturnal moths do not show this change.
There are many butterflies and moths that are active during the day, and they are very good at using dynamic visual effects to convey information to each other. Scholars have long believed that butterflies and moths that emerge diurnally and nocturnally are not good at this, because in the absence of light, they can basically only communicate through chemical signals. However, when scientists first found this change in the nocturnal moth, the situation changed, and it turned out that the nocturnal moth could also send visual signals. In addition, since this phenomenon is only found in males, the researchers believe that this may be related to the mechanism of sex selection.
Jennifer. Jennifer Kelly, an ecologist at the University of Western Australia, first noticed this unusual visual phenomenon while looking at moth specimens prepared for other projects. "When we discovered that this phenomenon was related to angles, we realized that to understand the principles behind it we had to understand the optical knowledge behind it," Kelly said. Subsequently, they contacted other scientists in the hope of support.
These include Gerd Schroder-Turk, a scientist at Murdoch University who studies the geometry of materials, and Bodo Wilts, a nanophotonian at the Adolf Mecker Institute in Switzerland.
Scientists collaborated on this optical phenomenon, and for this reason also deeply analyzed the nanoscale scales on the wings of nocturnal moths. They found that when viewed directly above, the scales reflected the light directly back to the original path like a mirror; when viewed from another angle, part of the light would pass through the wing surface to reveal the darker scales inside, thus showing the shape of the patches on the male moth's wings. When insects flap their wings vigorously (a common behavior of males when courting), these plaques flash and flash, creating striking signals even in very low-light environments.
"These moths provide a good idea for solving the problem of eavesdropping," said Elizabeth Tibbetts, a behavioral ecologist at the University of Michigan who was not involved in the study, "and their signals can only be received from a specific angle, allowing males to show their charm to the opposite sex without attracting the attention of predators." ”
Article excerpt from Global Science