''Cyphochilus'' is a
genus of
beetles with unusually bright
white scales that cover the whole
exoskeleton. ''Cyphochilus'' inhabit
Southeast Asia.
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
wavelengths with the same efficiency, thus resulting in a
white 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. The chitin filaments are just a few
micrometres 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 of the
random 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 nanofibrils to fabricate ultra-white paper for cosmetics and coatings.
References
Scarabaeidae genera
Melolonthinae
{{Melolonthinae-stub