''Cyphochilus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s with unusually bright

white White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White on ...

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

that cover the whole

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

. ''Cyphochilus'' inhabit

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

Etymology

Probably the same etymology as the former ''

Cyphochilus ''Cyphochilus'' is a genus of beetles with unusually bright white Scale (anatomy), scales that cover the whole exoskeleton. ''Cyphochilus'' inhabit Southeast Asia. Etymology Probably the same etymology as the former ''Cyphochilus (plant), Cyp ...

'' orchid: from the Greek ''kyphos'' meaning "bent" and ''cheilos'' meaning "lip", because of the reflexed lip.

External morphology

The whiteness of the scales is caused by a thin disordered photonic structure (≈7 μm) which scatters light of all

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...

s with the same efficiency, thus resulting in a

colouration. This is particularly interesting as the beetle's exoskeleton underneath the scales is black, meaning that the scattering events must be very efficient in order to achieve such high opaqueness. The white scales are composed of sclerotin, a modified form of the polymer

chitin Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...

, and are whiter than paper or any artificial material produced so far. That is they have a scattering mean free path shorter than any natural material thanks to the anisotropy in the spatial architecture of the fibres, which ensures a high packing efficiency whilst preventing optical crowding.

Ecology

Camouflage

The beetles are believed to have developed white coloration to be camouflaged among white

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

. The chitin filaments are just a few

micrometre The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

s thick – far thinner than a very fine sheet of paper. The elements are tightly packed, scattering light efficiently, but still able to keep a degree of disorder in their shape. It has been shown how this strategy is evolutionarily optimised to produce bright whiteness despite the low refractive index of sclerotin.

As inspiration for technologies

Scientists have exploited the

topology In mathematics, topology (from the Greek language, Greek words , and ) is concerned with the properties of a mathematical object, geometric object that are preserved under Continuous function, continuous Deformation theory, deformations, such ...

of the

random In common usage, randomness is the apparent or actual lack of pattern or predictability in events. A random sequence of events, symbols or steps often has no :wikt:order, order and does not follow an intelligible pattern or combination. Ind ...

network to fabricate materials of comparable performance for application as ultra-white paints and coatings. For instance, in 2018 Syurik et al. have developed a bioinspired

PMMA PMMA may refer to: * para-Methoxymethamphetamine, a stimulant drug * Philippine Merchant Marine Academy The Philippine Merchant Marine Academy ( fil, Akademiya sa Bapor Pangkalakalan ng Pilipinas) also referred to by its acronym PMMA) is a ma ...

-based material which scatters light efficiently whilst being flexible and switchable in appearance. Another recent example consists of the use of

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

nanofibrils to fabricate ultra-white paper for cosmetics and coatings.

References

Scarabaeidae genera Melolonthinae {{Melolonthinae-stub