Butterflies, beetles and dragonflies declining in Europe!

The Violet Copper Lycaena helle (Endangered) is a rare and threatened butterfly in Europe. Photo : Chris van Swaay

Habitat loss is having a serious impact on Europe’s butterflies, beetles and dragonflies, the International Union for the Conservation of Nature (IUCN) said today. Nine percent of butterflies, 11 percent of saproxylic beetles (beetles that depend on decaying wood) and 14 percent of dragonflies are threatened with extinction within Europe, the Switzerland-based conservation organization said in a news release.

Read more on Vijay Barve’s Biodiversity India blog post here.

Download the section of the IUCN Red List on European butterflies here.

The situation is far worse in India. Even worse our scientific footprint is so weak, we don’t even have comparable data. God preserve my beloved country’s wildlife!

Image credit : IUCN. Displayed under “Fair use”.

A Decorative Beetle

 

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)

Note: Based on comment given by Shyamal below, the genus name “Calothyrza” is derived from “calo” meaning white, and “thyrza” from a Hebrew word “tirzah” meaning “she is my delight” [https://en.wikipedia.org/wiki/Tirzah_(name) ].The species name “margartifera” means, “bearing pearls” and is derived from the Greek word for “pearl” (margarites) and the Latin word “to bear” (ferre). Very apt for the brilliant white chitin on this lovely beetle.

The beetle which changed colours

One comes across the wonders of natures almost accidentally. In June 2006, on the thirteenth to be precise, my son Aashay and I had driven along the Pokaran – Jaisalmer road to look at Tawny Eagles, who are easily found every few hundred metres perched on the wires or poles. On the way back, we stopped to say hello to a local acquaintance. He stood at his present place of labour, a dolomite mine the concession of which he had taken. The mine, near Chacha village, some 20 odd kms from Pokaran, consisted of an area approx 200 yards in diameter in the middle of which there was a large pit some ten yards across and about ten feet deep. Inside, the pit had tunnels leading from the sides which my friend claimed were quite long and winding and undermined almost all the area of the mine. On the surface, occasional holes with large piles of white dolomite stones around the entrances hinted at the warren below.

The dolomite quarry where we found the beetle.

As fathers are prone to do, conversations turn to worldly matters or ‘shop’ so Aashay went wandering around the mine. A fatherly warning followed Aashay that he should stick to the beaten tracks only.

Fifteen minutes later, I walked upto Aashay to fetch him. It was 8.30 and time that we made our way back home for breakfast. Aashay was bent over, peering at something on the ground. It was a beetle scurrying on the ground.

”Pappa” he said, ”there’s something strange about this beetle!”

We followed it as it meandered amongst through the broken stone and sand. It was beautiful, almost completely white with a few black markings. A white beetle being a novelty, I was keen to get close and take a photograph but the beetle did not cooperate. Realising it was being pursued, the beetle changed tack and now hurried along on a twisting path towards some Aak bushes (Calotropis spp). A picture on the ground was difficult to get so Aashay chased it trying to scoop up the dodging creature. This he did, only to lose it a few seconds later. We did however succeed in taking a few snaps.

What was truly amazing was that the beetle, which was almost completely white when Aashay had spotted it, gradually turned darker and darker until finally it was almost completely black with only a very thin white edging.

The creature finally reached sanctuary – a cluster of Aak roots with twisted branches, dried leaves and small crevices into which it disappeared. The Rajasthani locals who worked the mines told us that the beetle turned black with fright but would recover to its original pattern after 15 minutes or so.

Immediately after we encountered the beetle it began turning black.

Scooped up in Aashay's hands for taking a good snap, it has almost turned completely black.

Later I put up the images on Wikipedia WikiProject Arthrpods talk page, hoping for an identification. Doug Dynega, an entomologist and museum curator in the States, responded whith what appears to be the key to the mystery:

”It’s a Tenebrionid, but I can’t be certain of the subfamily. From what I can see in the photos, the white “markings” are, like in many desert Tenebs, not markings, but fine cuticular wax deposits. I’d never heard of the beetle being able to change the amount of wax on it, so I have a better explanation, based on what one can observe; the wax layer is hygroscopic (absorbs moisture), and when it does so, it loses its reflectivity. Holding the beetle in your hand will greatly increase the humidity in the airspace near the beetle. This makes some sense as a desert adaptation; when humidity is low, the beetle reflects more sunlight, and when humidity is high, it reflects less. I’ve just never heard of the phenomenon, and can’t confirm it myself. What you need to do is catch one, kill it, and experiment. If it’s that sensitive, even breathing on it should have a noticeable effect. If it can be confirmed, it might even be something to publish, assuming no one has documented it before.”

Sadly, we left the area soon after and could not go back to explore this mystery any further. A pretty little puzzle waiting for someone to unravel it!

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Notes.

1. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License“.

2.  Comment by Doug Dynega published under GFDL copyright from Wikipedia at the Talk page of WikiProject Arthropods on Wikipediaaccessed on 08 Jan 2009: