Archive for the ‘nano-technology’ category

A Decorative Beetle

12 July 2009


Calothyrza margaritifera - a Cerambycid beetle recently found in Pen.

Calothyrza margaritifera - a Cerambycid beetle recently found in Pen.

On a afternoon in early July, at Vavoshi near Pen, my father-in-law, Mr Nandan Kalbag spotted an intriguing beetle in black and white. It resembled a stylised Guy Fawkes mask of the kind that I remember seeing in ‘V for Vendetta‘. It was perched on a hanging flower-vase and was motionless. It stayed there awhile and after a couple of hours it was gone.

One of the big advantages of being a son-in-law of a man keenly interested in the natural world around him is a steady stream of images and anecdotes which permit me to vicariously enjoy those moments with him. In course of time, the image came to me, was bunged onto the InsectIndia yahoo-group. There it was picked up by a friend and forwarded to a Dr Hemant Ghate of the Zoology Dept of Modern College in Pune, a man desperately keen on beetles. After consulting with Dan Heffern, an American engineer turned coleopterist, a verdict was delivered – the culprit was identified as Calothyrza margaritifera which was described by Westwood in 1848.

Common names are a luxury available to enthusiasts of mammals, birds, butterflies, a few reptiles and amphibians. In the world of arthropods, there are very few common names. Calothyrza margaritifera – the name meant nothing to me. I don’t really know much about beetles – I am quite prone to mis-spelling them too; I forget they are ‘beetles’ not ‘beatles’. India has no recent handbooks on beetles for the amateur. It took a little patient digging online to find out a little more about this curious insect.

Calothyrza margaritifera is a longicorn or long-horned beetle; it belongs to the family Cerambycidae. Most but not all cerambycids have antennae longer than their bodies. These beetles are wood-borers and some are economically significant pests. Some small cerambycids mimic ants, wasps and bees. A member of this beetle family is considered to be the largest insect in existence today.

C. margaritifera belongs to the tribe Phrynetini of the subfamily Lamiinae. The beetle volumes of the Fauna of British India of the early twentieth century vintage are the only tomes available to the amateur naturalist of India. Unfortunately Charles Joseph Gahan, the author of the Cerambycidae section only wrote one volume which unfortunately excludes the Lamiinae, those taxa being reserved for the never written second Volume.

The known range of C. margaritifera embraces the Central Himalayas of India and Nepal, and extends across Myanmar to Thailand. The discovery of this beetle in Raigad district of Maharashtra is then an important range extension. Fortunately, the species has a very distinct look so that, strictly speaking, a specimen may not be needed to record the find.

Like most picturesque long-horned beetles, Calothyrza margaritifera demands a substantial price on the international specimen trade – prices typically range from ten to 35 dollars each. Most Calothyrza specimens show Thailand as their area of origin. One may think that the Biological Diversity Act of 2002 as amended may protect Indian beetles but there is ample evidence to the contrary on the internet, this site being one such example. Single Calothyrza margaritifera specimens, and occasionally pairs appear for sale in insect catalogues and sometimes on E-Bay!

We are often reminded of the need to preserve and protect our biodiversity by stories of how such and such organism s being investigated for new science, fresh discoveries and path-breaking insights. It may interest you to know that Calothyrza margaritifera is one of those. In this case, the vivid white of the beetle cuticle is being investigated at the nano-technological level. The vivid whiteness of the beetle’s cuticle is not the result of a hue but rather the nano-structure of pill-shaped chitin growths. The abstract of the paper, presented in a symposium on ‘Bioinspired and biointegrated materials as new frontiers for nanomaterials’ (Symposum M) on 10 Jun 2009 at 12:05 hrs this year in Strasbourg, can be found here.

What worries me most is that there are hundreds of such delicious scientific curiosities waiting to be discovered in our jungles which may never come into existence before the forests and their associated biodiversity are lot forever.

Image credit – Mr Nandan Kalbag (under Creative Commons 2.5 SA)