Many animals have developed camouflage tactics to protect themselves from their predators. However, some butterflies and moths have taken it even further: they have developed transparent wings, making them almost invisible to other animals.
A group of scientists from the Marine Biology Laboratory (Massachusetts, United States) has analyzed how butterflies develop their so-called glass wings. In addition, the research results have been published in the Journal of Experimental Biology.
Investigation Development
To carry out the study, the scientists looked closely at various wing samples through the microscope. Thus, they realized that the origins of the development of transparency in terrestrial butterflies had never been investigated.
Through a confocal microscope they were able to develop a time scale in the creation of their wings. From the pupal stage (that is, when the insect is no longer a larva) to adulthood. In this way, they were able to discover that crystal butterfly wings develop differently from colored species, with fewer scale precursor cells in the areas that will later become transparent.
“The glass butterfly makes fewer scales and produces them in very different shapes than other butterflies, similar to bristles,” explained Nipam Patel, director of the laboratory. The researcher also added that, by analyzing the nanostructure of the wings, they were able to observe that they prevented glare from sunlight.
“As humans, we think we’re awesome because we figured out how to put an anti-reflective coating on glass, but butterflies figured it out tens of millions of years ago,” Patel said.
The scales and their nanostructures are just one part of the wings. They also have a second layer of hydrocarbon nanopillars located on the surface of the wing, providing more anti-reflective properties. The researchers examined the reflectivity of the wings before and after removing the waxy coating with hexane (a chemical).
Thus, they were able to show that this upper layer was essential to reduce glare on their wings.
Future investigations
Now, researchers are focused on discovering how these beautiful insects evolved to achieve their transparent wings.
“If we can learn more about how nature creates new types of nanostructures, it can be very relevant to human applications,” said Aaron Pomerantz, lead author of the study.
