By IANS
London : The Hercules Beetle, which can carry 850 times its own weight and is possibly the “strongest” of its kind in the world, is teaching scientists a thing or two about its remarkable camouflaging abilities.
The beetle has a colour-changing trick that scientists have long sought to understand.
A report in the latest issue of the New Journal of Physics has detailed an investigation into the structure of the beetle’s peculiar protective shell that could help in the design of “intelligent materials”.
The beetle’s protective exoskeleton or shell changes from green to black as its surrounding atmosphere gets more humid.
Researchers from the University of Namur in Belgium have used the latest imaging techniques to study its shell to determine the structure responsible for the colour and to analyse how light interacts with this structure.
They found that light interferes with the structure to produce the green colour of the shell. When water penetrates through the open porous layers, it leads to a black colouration.
The beetle, usually found in the rainforests of South America, is still rather mysterious though.
Although a dry specimen of the shell could be relied on to change when humid conditions were introduced, the living species that researchers also had in the lab were not as consistent.
Question marks also remain on why the beetle changes colour. Some have suggested that it is to do with protection – it becomes more humid at night and is therefore good for the shell to turn black. Others have suggested that it is to do with warmth absorption at night.
The techniques used to study the beetle’s morphology included new scanning techniques for electron images which have been refined to yield great depth and therefore help to create 3-D images of miniscule structures.
Marie Rassart, a researcher, said: “The sort of structural behaviour displayed by the Hercules Beetle could be an important property for ‘intelligent materials’.
“Such materials could be put to work as humidity sensors. This could be useful for example in food processing plants to monitor the moisture level.”