Green Scarab Beetle from India is structurally coloured according to Wikipedia

ID pls
Location: Bannerghatta National park., Karnataka, south India
November 14, 2011 12:19 am
hi, i found this fellow in my place. place found was South India, Karantaka, Bangalore, Scrub forest Bannerghatta National park. pls can i know the common and scientific name of this fellow
Signature: rameshb belagere

Unknown Green Scarab Beetle

Dear rameshb belagere,
This is a Scarab Beetle in the family Scarabaeidae, but our initial search of the internet has not turned up a definitive species identification.  We believe it is the same species as this unidentified photo posted on vidarbha wildlife.  One of our readers may be able to assist in this identification.

Identification Courtesy of Karl
Hi Daniel and rameshb belagere:
I think you are right about the unidentified photo you linked to (on vidarbha wildlife). It looks like a Flower Chafer (Scarabeidae: Cetoniinae), probably Heterorrhina elegans. You can just make out the four black, raised bumps (calli, or singular callus) on the elytra that apparently are diagnostic for the species. Online images are scarce but a set of three appears on various sites, including Wikipedia. If you care to read a detailed description you can access an online version of the relevant volume (G. J. Arrow 1910) of “The Fauna of British India including Ceylon and Burma”. The relevant text includes: “…the sutural margins of the elytra posteriorly and the apical calli black (generally also the humeral calli, but less distinctly.)” and “H. elegans is distinguishable from all other Indian species of the genus by its extremely glossy surface, as well as by the black spot near the end of each elytron.”  I can’t be absolutely certain, but I believe that is it. Regards. Karl

Thanks so much Karl.  We are fascinated by the Wikipedia claim that the coloration is not due to pigment, but to structure, or as it is more technically stated:  “The physics of the colouration of the cuticle is a subject of interest as the colours are entirely structural, not produced by pigments, and nearly 200 year old specimens show no degradation of the colours.[3] The underlying structures made up of nearly 50 microscopic double layers[4] have been studied in the search for structural paints that do not need pigments which are often environmentally toxic chemicals.”  The coloration of the Morpho is also due to structure and not pigment.

3.  Neville, AC & S Caveney (1969). “Scarabaeid beetle exocuticle as an optical analogue of cholesteric liquid crystals”. Biological Reviews 44 (4): 531–562. doi:10.1111/j.1469-185X.1969.tb00611.x. PMID 5308457.

1 thought on “Green Scarab Beetle from India is structurally coloured according to Wikipedia”

  1. thank you for the classic ‘Fauna of British India including Ceylon and Burma’ I am working on Coleoptera from Nashik. This is precious.


Leave a Comment