Cyphochilus (beetle)

Cyphochilus is a genus of beetles with unusually bright white scales on the body, occurring in Southeast Asia.^[2] The whiteness of the scales is caused by a thin layer of a highly reflective natural photonic solid in its scales, though the exoskeleton of the beetle underneath the scales is black.^[3]

They use the polymer chitin to produce these white scales, which are whiter than paper or any artificial material produced so far. The beetles are believed to have developed white coloration to be camouflaged among white fungi. There is a complex molecular geometry to their scales, which are able to scatter light with supreme efficiency in spite of their thinness. To produce white scales, Cyphochilus beetles must scatter all colours with equal strength, something rarely found in nature. What makes these scales so white is the special arrangement of the chitin elements inside them, together with their varied shapes and sizes^[4]. The chitin filaments are just a few micrometres thick – far thinner than a very fine sheet of paper. The elements are tightly packed^[5], scattering light efficiently, but still able keep a degree of disorder in their shape.^[6] It has been shown how this strategy is evolutionarily optimised to produce brigth whiteness despite the low refractive index of [chitin] ^[7]

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