Archive for the ‘butterflies’ category

Of Lolita and Lepidoptera

5 February 2011

The two faces of Vladimir Nabokov

Poster of the 1962 movie.

You may have recognised the name “Lolita“. It was a complex and serious novel of the mid-fifties,  in which a taboo area of human sexuality was explored for the first time – child sexual abuse. In the fifties, at the height of the age of middle-class morality, the powerful and ambiguous novel drew criticism, opprobrium and later acclaim. The author was Vladimir Nabokov who has since been recognised  as one of the great novelists of the Twentieth Century.

But there is another side of Nabokov – little known to most casual readers, and even to some of us who love and study butterflies – that he was from childhood to the end of his days an aurelian.

He loved butterflies! Since early childhood in Russia, Nabokov collected and studied them.

Carl Zimmer writes :

Nabokov inherited his passion for butterflies from his parents. When his father was imprisoned by the Russian authorities for his political activities, the 8-year-old Vladimir brought a butterfly to his cell as a gift. As a teenager, Nabokov went on butterfly-hunting expeditions and carefully described the specimens he caught, imitating the scientific journals he read in his spare time. Had it not been for the Russian Revolution which forced his family into exile in 1919, Nabokov said that he might have become a full-time lepidopterist.

During the period of exile in France, before he moved to USA, forced to move by the menace of Hitler‘s Panzer divisions roaring across France, Nabokov and his wife went butterflying across the Pyrenees, financed by his proceeds from his second book – “King, Queen, Knave“. Nabokov was a competent taxonomist and became the  curator of lepidoptery at Harvard University‘s Museum of Comparative Zoology. Later on, the proceeds of “Lolita” would allow Nabokov and his wife on an extensive trip butterflying across the Rockies.

A butterfly’s view of Vladimir Nabokov.

But how should I introduce Nabokov’s love for these small, delicate, weak-flying shimmering butterflies in hues of blue, Prussian, sapphire, purple,violet?

The Karner Blue (Lycaeides melissa samuelis), a butterfly described by Nabokov in 1944, now granted species status as “Lycaeides samuelis”. (Image:J&K Hollingsworth)

Perhaps through a poem he wrote :

On Discovering a Butterfly

I found it and I named it, being versed in taxonomic Latin; thus became godfather to an insect and its first describer — and I want no other fame. Wide open on its pin (though fast asleep), and safe from creeping relatives and rust, in the secluded stronghold where we keep type specimens it will transcend its dust. Dark pictures, thrones, the stones that pilgrims kiss, poems that take a thousand years to die but ape the immortality of this red label on a little butterfly.

Vladimir Nabokov

This is a poem written, not by a butterfly-lover, but by a butterfly-loving taxonomist. The red label on a butterfly specimen is only attached to a specimen kept specifically as an example of the newly named and described species. Such a label enters the describer, and the specimen into the Entomology Hall of Fame, so to say. A butterfly specimen with red label attached is forever part of entomological history.

A holotype with red type label. (Image:Robert Nash)

The Wandering Minstrel recalls Stephen Jay Gould‘s brilliant essay in “I have landed” (2002) about Nabokov…

Museum curators traditionally affix red labels only to “holotype” specimens — that is, to individuals chosen as official recipients of the name given to a new species. The necessity for such a rule arises from a common situation in taxonomic research. A later scientist may discover that the original namer of a species defined the group too broadly by including specimens from more than one genuine species…. By official rules, the species of the designated holotype specimen keeps the original name, and members of the newly recognized species must receive a new name. Thus, Nabokov tells us that no product of human cultural construction can match the immortality of the permanent name-bearer for a genuine species in nature. The species may become extinct, of course, but the name continues forever to designate a genuine natural population that once inhabited the earth.

The Wandering Minstrel goes on to say…

A commenter in the post (my words) goes on to note that the  poem reflected the “vanity of human wishes”, but it speaks, too, of something more specific – the bid for immortality that motivates even the “purest” of scientists. Scientific biographers speak, often with palpable surprise, of the “pettiness” that scientists can display in their quest for the all-important Precedence, but that is merely due to an idealised notion of a scientist who is supposed to transcend all human emotions in his quest for Truth. In reality, Scientists are as alive to the seduction of fame as anyone else – and the brand of fame they seek makes “the glories of our blood and state” look positively ephemeral. Of course poets have long espoused the conceit that words are the surest form of immortality – “Not marble, nor the gilded monuments / Of princes, shall outlive this powerful rhyme” quoth the Bard – but Nabokov trumps even that with his “thus became […] its first describer — and I want no other fame.” And although he says “it will transcend its dust”, the temptation is irresistible to read, superposed on the “it”, a triumphant “I”.

Being a taxonomist, Nabokov, loved not just the external magnificence of the patterns and colours of butterfly wings but also  the hidden intrinsic elegance with which Nature provides form and function in its creatures. Like the protagonist in Zen and the Art of Motorcycle Maintenace, he sought classic beauty in the form and function and not the romantic beauty of the appearance in his passionate study of the anatomy of these delicate insects. It takes a singular passion to motivate a person to spend countless painstaking hours studying thousands of specimens, peering through microscopes and making detailed diagrams of their body parts. Nabokov did all this. A taxonomist’s abiding faith rests in the belief that the shape and structure of the insect bodies hide truths of nature which he resolves to discover. That, imho, is the Holy Grail for taxonomists. And Nabokov found it, but never knew that he had done so.

Vladimir Nabokov at the Museum of Comparative Zoology, Cambridge, Massachusetts, 1945. (Image:NYPL, Berg Collection)

For years Nabokov studied the Polyommatus genus of butterflies, dissecting and drawing the intricate shapes of the male sexual organs of the little insects. The shape of the male organ of butterflies is distinct to a species and has specifically evolved uniquely for each species. In groups such as the Polymmatinae, which resemble each other and are difficult to distinguish, the examination of the male organ alone helps identify the species reliably. Nabokov sat patiently, peering through microscopes to the detriments of his eyes, making neat diagrams, describing the finer details in the formal language characteristic of science, shorn of adornment and replete with terms rarely understood by common folk. Nabokov went on to describe hundreds of new species.

Click here to see a slideshow on Nabokov’s Butterflies in the New York Times

As he described, he mused over how they must have evolved, and how the complex pattern of resemblances and differences would have accumulated and formed his own theories. Zimmer writes

He argued that what were thought to be closely related species were actually only distantly related. At the end of a 1945 paper on the group, he mused on how they had evolved. He speculated that they originated in Asia, moved over the Bering Strait and headed south all the way to Chile. Allowing himself a few literary flourishes, Nabokov invited his readers to imagine “a modern taxonomist straddling a Wellsian time machine.” Going back millions of years, he would end up at a time when only Asian forms of the butterflies existed. Then, moving forward again, the taxonomist would see five waves of butterflies arriving in the New World.

Now, there could be very many models of how the butterflies evolved. One example cited often is that they could have evolved in the tropical forest of the Amazon where biodiversity and speciation is very high. In that case the butterflies arrived there from Asia once and a large number of species arose later, each of which would be closely related. Though Nabokov was a distinguished expert of his day, this vision of his was too much to chew for his contemporaries. I surmise that neither zoogeography or the geological science of that time had accepted the idea of repeated waves of migration across the Bering Strait.  Since there was no way to prove the hypotheses at that point of time, it languished after his retirement in the sixties and his death in 1979 and was soon forgotten. Subsequent generations of lepidopterists grew up considering Nabokov as a competent and diligent Lepidopterist but not as one who had come up with path-breaking ideas.

Drawings of the genitalia of various blue butterflies in Nabokov’s famous 1945 paper in Psyche.

The scene moves on to the early nineties. The advent of new tools for DNA sampling and  genomic studies began to unravels many hidden facets of nature. A re-examination of the blues by Dr Kurt Johnson of the American Museum of Natural History led to the study of Nabokov’s classification. Johnson collected and examined many specimens. As he later described in the 2000 book “Nabokov’s Blues,” written with Steve Coates, Dr. Johnson set about reviving Nabokov’s classification and found it to be substantially correct. In another case, Nabokov had described the Karner Blue as a seperate species while other authorities later classified it as a subspecies of the  Mellisa Blue. DNA analysis proved Nabokov’s view to be correct.

Nabokov’s hand-drawn illustration of wing-pattern of “Echinargus” species novium described in the 1945 Psyche paper.

In 1990, a Dr Naomi Pierce became a Harvard biology professor and curator of Lepidoptera. Nabokov’s birth centenary was coming up in 1999 and Naomi started acquainting herself in detail about his work. When she came across Nabokov’s hypothesis of evolution of the Polyommatus blues in a book titled “Nabokov’s Blues” by Kurt Johnson and Steve Coates, she realised that the hypothesis was testable with today’s scientific techniques. She organized four separate trips to the Andes to collect the blues, and then she and her colleagues at Harvard sequenced the genes of the butterflies, as well as comparing the number of mutations each species had acquired. The mutation rate data indicated the approximate duration passed since the creatures diverged in evolution. Their research proved Nabokov’s “bold hypothesis” to be true. Zimmer writes..

Instead, they found that the New World species shared a common ancestor that lived about 10 million years ago. But many New World species were more closely related to Old World butterflies than to their neighbors. Dr. Pierce and her colleagues concluded that five waves of butterflies came from Asia to the New World — just as Nabokov had speculated. “By God, he got every one right,” Dr. Pierce said. “I couldn’t get over it — I was blown away.” Dr. Pierce and her colleagues also investigated Nabokov’s idea that the butterflies had come over the Bering Strait. The land surrounding the strait was relatively warm 10 million years ago, and has been chilling steadily ever since. Dr. Pierce and her colleagues found that the first lineage of Polyommatus blues that made the journey could survive a temperature range that matched the Bering climate of 10 million years ago. The lineages that came later are more cold-hardy, each with a temperature range matching the falling temperatures.

A very nicely written post from the blog “Why Evolution is True”, with more science in it than this post, can be found here.

Click to reach a very nice slideshow on Nabokov’s Lepidoptery from the New York Public Library.

Another of Nabokov’s talents was his skill in illustrating butterflies. He often painted butterflies and presented them to friends.

Butterflies drawn by Vladimir Nabokov for his wife. (Image: Alex Bakharev)

Nabokov’s love for butterflies shows in his literature also. Perhaps the earliest was one of his Russian short stories – The Aurelian. “Aurelian” is an archaic word for a butterfly-lover. In this short story, Nabokov develops the concept of metamorphosis as transcendence into life on a higher plane. The proatogonist in “The Aurelian” is Paul Pilgram, an entomologist and butterfly dealer who never left his native Berlin. Pilgram lives a futile, dreary life with a unsuccessful business and an unsatisfactory marriage, However he dreams of leaving this all behind and going on a butterfly-hunting expedition to exotic places such as France, Dalmatia, Russia and Tibet which his fate and circumstances do not permit. At last, Pilgram manages to cheat a customer and get the money and prepares to go on a journeying dumping his wife and his business behind. As he departs, Pilgram dies of a heart attack. To give you a taste of Nabokov’s style of writing, I include the last three paragraphs of his short story :

NIGHT came; a slippery polished moon sped, without the least friction, in between chinchilla clouds, and Eleanor returning from the wedding supper, and still all atingle from the wine and the juicy jokes, recalled her own wedding day as she leisurely walked home. Somehow all the thoughts now passing through her brain kept turning so as to show their moon-bright, attractive side; she felt almost light-hearted as she entered the gateway and proceeded to open the door, and she caught herself thinking that it was surely a great thing to have an apartment of one’s own, stuffy and dark though it might be. Smiling, she turned on the light in her bedroom, and saw at once that all the drawers had been pulled open; she hardly had time to imagine burglars, for there were those keys on the night table and a bit of paper propped against the alarm clock. The note was brief: ‘Off to Spain. Don’t touch anything till I write. Borrow from Sch. or W. Feed the lizards.’ The faucet was dripping in the kitchen. Unconsciously she picked up her silver bag where she had dropped it, and then kept on sitting on the edge of the bed, quite straight and still, with her hands in her lap as if she were having her photograph taken. After a time someone got up, walked across the room, inspected the bolted window, came back again, while she watched with indifference, not realizing that it was she who was moving. The drops of water plopped in slow succession, and suddenly she felt terrified at being alone in the house. The man whom she had loved for his mute omniscience, stolid coarseness, grim perseverance in work, had stolen away…. She felt like howling, running to the police, showing her marriage certificate, insisting, pleading; but still she kept on sitting, her hair slightly ruffled, her hands in white gloves. Yes, Pilgram had gone far, very far. Most probably he visited Granada and Murcia and Albarracin, and then traveled farther still, to Surinam or Taprobane; and one can hardly doubt that he saw all the glorious bugs he had longed to see—velvety black butterflies soaring over the jungle, and a tiny moth in Tasmania, and that Chinese ‘Skipper’ said to smell of crushed roses when alive, and the short-clubbed beauty that a Mr. Baron had just discovered in Mexico. So, in a certain sense, it is quite irrelevant that some time later, upon wandering into the shop, Eleanor saw the checkered suitcase, and then her husband, sprawling on the floor with his back to the counter, among scattered coins, his livid face knocked out of shape by death.

Read the complete English translation of “The Aurelian” here. Still like to learn more about Nabokov, his  literature and lepidoptery? Erin Overby’s post  in the New Yorker tells us more about Nabokov’s depiction of butterflies in other works. And here is a short and interesting free online course on Nabokov from the now defunct Fathom online learning initiative of Columbia University. Here’s a post and yet another from one of my favourite Science Bloggers Bioephemera. Maria Popova’s commentary on Gould’s essay can be found here. And here is more, and even more. Nabokov may now rest in peace, his reputation as a practitioner in his first great love, the butterfly world, having been vindicated.

the grave of Vladimir Nabokov (Russian-American writer) and his wife Vera Nabokova in Cimetière de Clarens (Switzerland). (Image:Gorodilova)

Image Credits

  • Click on the images to reach the sources.
  • Some are from Wikimedia Commons published under their respective free licenses.
  • All others under Fair Use from the source indicated.

Meet the Monkey-Puzzle (Rathinda amor)

3 January 2011

Visited the beautiful Butterfly Conservatory of Goa (Yashodhan Heblekar’s place) just after Christmas. It’s a very nice setup, great hospitality and good food. I spotted some very nice butterflies there.

Bait placed at the verdant Butterfly Conservatory of Goa!

Here is one which made a great impression on me – the Monkey-puzzle (Rathinda amor).

Monkey-puzzle (Scientific name - Rathinda amor) (Image:Vijay Barve on Wikimedia Commons)

The BCGoa is located on the hill-slope of the Bhootkhamb plateau which has wet deciduous forest. The Monkey-puzzle was the most prominent lycaenid (blues family-member). It is quite small, not very much larger than the grass-blues. At that time of the day, noon, it was active in the shade under the trees. We saw at least twenty. The butterfly would land on a leaf, shuffle and waggle its tails.

The Monkey-puzzle has three tails on each hindwing, white-tipped and linear. There is a tornal spot on the hindwings near the tail. The tail complex can be considered to resemble the head and antennaes and are thought to confuse predators.

Moist deciduous forest at Bhootkhamb plateau

Moist deciduous forest at Bhootkhamb plateau

Often, butterfly-lovers are familiar with the vividly patterned underside of the Monkey-puzzle which is characteristic and unmistakeable. Strangely, above it is quite plain brown except for a few undistinguished spots. I attach an image of the upperside of Monkey-puzzle.

The Wikipedia article on the Monkey-puzzle ( read about the butterfly here :  ) describes the butterfly above as :

“Upperside – The butterfly is dark brown. It has a white-spot end cell. It has narrow white spots on 2 and 3 which form a short band on the forewing. On the UPH it has two black tornal spots and narrow dark reddish spot above them.”

Markings of upperside of the Monkey-puzzle butterfly (Rathinda amor). Bhootkhamb plateau, Pisgal, Ponda district, Goa, India.

Notice : This is an excerpt of an email sent to ButterflyIndia email group which you must surely join if you are interested in Indian Butterflies.

Violent Butterflies!

6 June 2010

Patterns from Meso-American cultures

I came across something really interesting some time ago – butterfly patterns occurring in the architecture of the Meso-American cultures. However, there is a gruesome twist – they do not represent beauty or peace or harmony but instead represent warfare and bloodshed.

To get a feel of the patterns , an introduction to this unique civilisation on the other side of the world to India is in order.

Meso-America is a region and culture area in the Americas, extending approximately from central Mexico to Honduras and Nicaragua. A number of pre-Columbian societies, such as the Olmecs, Mayas, Aztecs and many others flourished before the Spanish colonization of the Americas in the 15th and 16th centuries.

 

Location of Meso-America with relation to North and Central Americas.

The region is peppered with the fascinating ruins of great cities such as Teotihuacan, Tikal, Tenochtitlán, Palenque, Chichen Itza and many others. Over time the peoples declined and by the seventeenth century these cultures had vanished or dispersed. The story of the discovery and excavation of these great cities, some of which are completely masked by thick forest, to the extent that you can travel through them and not realise that they are there, while others were still occupied over the centuries after their sack, makes fascinating reading.

 

A view of the Classic Maya city of Palenque which flourished in the sixth and seventh centuries. (Image:Jabob Rus in Wikimedia Commons, CC-BY-SA-2.0)

The Meso-American cultures had a rich heritage. They had a pictorial script – this is one of only five regions in the World where writing originated independently. The Mayans had a number of calenders and an elaborate culture of astronomy. They had elaborate systems of water-irrigation. They also had pyramids but of the stepped kind.

 

Mayan glyphs from Palenque. (Image:User:Kwamikagami in Wikimedia Commons)

Pyramid in the Mayan city of Chichen Itza, Mexico. (Credit:User:AlexCovarrubias on Wikimedia Commons)

These cultures represent the change of man’s lifestyle from hunter-gatherer to sedentary in the Americas. Corn or Maize, one of our major staple foods was discovered here.

 

Corn, or maize, descended from a Mexican grass called teosinte. (Image:New York Times)

It is interesting to note that Meso-Americans played a ballgame for over 3000 years. A modern version of the game, ulama, continues to be played in a few places.  It was probably similar to volleyball, where the object is to keep the ball in play. In the most well-known version of the game, the players would strike the rubber ball (weighing 4 kg or more) with their hips, forearms, rackets, bats, or hand-stones. Over 1300 ball-courts of different sizes have been found throughout Meso-America.They resemble a modern day squash court in that they all feature long narrow alleys, with side-walls against which the balls could bounce. The game was played casually for simple recreation, perhaps by children and women too but it also had important ritual aspects. Major formal ballgames would be held as ritual events, often featuring human sacrifice.

 

Drawing of Aztec ballplayers performing for Charles V in Madrid in 1528 drawn by Christoph Weiditz. (Image:Wikimedia Commons, Public Domain).

The Aztec and Mayan cultures are clouded in our minds today due to their practice of human sacrifice. The Aztecs, in particular, were fearsome practitioners. In the Mayas, human sacrifice was reduced and more ritualistic. For a feel of the horror of human sacrifice, I would advise you to see Mel Gibson’s film “Apocalypto“. The film has raised many controversies but gives a graphic feel of Meso-American life.

There is no doubt that the Olmecs, Mayans, Aztecs, Toltecs, Mixtecs and the other cultures of Meso-America were great cultures. In some aspects, terrible, but definitely great.

Nature and wildlife are a recurrent theme in these cultures. Take the case of Teotihuacanits murals depict many living organisms such as quetzals, jaguars, doves, fish, felines, serpents, shelled animals, shells, sea creatures, water lilies, and seeds. Flowers, shells, and feathers abound.

 

Kukulcan's Jaguar Throne at Chichen Itza. (Image:Bonomojo & Alvinying on Wikimedia Commons)

The butterfly was an especially popular motif – more than 45 works from sites throughout Puebla and Oaxaca in Meso-America include the butterfly in their compositions. The Courtyard Palace of the Quetzalpapalotl in the center of in Teotihuacan is one such example – thought to have been the royal residence of the city, the Palace of Quetzalpapalotl, the quetzal butterfly, it has a large, square patio, lined with columns decorated with bird and butterfly motifs.

A butterfly motif from Ancient Mexico. (Artist : Jorge Enciso)

The butterfly in Meso-American cultures appears to be symbolically associated with militaristic expansion. The butterfly symbol was worn by warriors as a pectoral or head ornament in Teotihuacan architecture and later carried over into the Chichen Itza culture also. Besides war and warriors, butterflies also represented fire, soul, death, travelers and hummingbirds.

Many Aztec Gods and Goddesses had animal features. In Teotihuacan,  Itzapapalotl,  the great Goddess, is a patroness of warfare; she assumes a butterfly guise and demands sacrifices, both locally and in distant lands.

 

Itzpapalotl - the Obsidian or Clawed Butterfly. A skeletal figure with jaguar claws and butterfly wings. (Image:www.azteccalendar.com)

Another minor deity – “Metztli”, ruler of the moon, is depicted as an old man with a giant seashell attached to his back which also sports a pair of colorful butterfly wings.

These then are the highly stylised butterfly wings found in the architecture of Aztecs and other cultures.

Nine Butterfly patterns from Meso-American cultures.

A-B. Clay flat Stamp with butterfly motif from Teotihuacan.

C. Hieroglyphic from the town of Ocuilán, representing a caterpillar with the head of a butterfly.

D-F. Clay flat Stamp with butterfly motif from Azcapotzalco.

G. Incomplete stamp with a butterfly motif containing complex wing patterns from Teotihuacan.

H-I. Clay flat stamp with butterfly motif from Azcapotzalco.

Mexico, which forms part of Meso-America and whose flora is shared with other Meso-American countries, has a rich and wonderful diversity of Lepidoptera (see Mariposas Mexicanas and Nelson Dobb’s web-site).

An interesting book, unfortunately inaccessible to us being in Spanish, has been written by Dr. Carlos Beutelspache, a Mexican lepidopterist,  who has documented the multifarious ways that butterflies and moths were woven into ancient Mexican Cultures. These range from transient and simple uses of the lepidopteran form for adornment of pottery and in featherwork, to deeply religious symbolism hewn in stone. A review is available here.

A likely model for Pattern A - Three-tailed Tiger-Swallowtail, Pterourus pilumnus (Boisduval, 1836). (Image:Nelson Dobbs)

 

Another model? Mexican Kite-Swallowtail, Protographium epidaus (Doubleday, 1846). (Image:Nelson Dobbs)

 

The Bloody Spot (Phocides polybius), a beautiful skipper from Mexico. (Image:mariposasmexicanas)

Sadly though, butterflies in Meso-America reflect not aesthetic values as in the civilisations further East across the Atlantic Ocean, but bloodshed, warfare and human sacrifice.

Ironically, the Aztec butterfly may also be considered as symbol of this blog being a curious mixture of butterflies and the life of a military man (though with the violence carefully excluded).

I found the main image of butterfly patterns on this extinct web-site, still existing but abandoned since the mid-nineties. The image was bereft of information - looking up on the internet brought out the gruesome association.

Images: As attributed. Copyrighted images reproduced under “fair use” policy.

Butterflies, beetles and dragonflies declining in Europe!

25 March 2010

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”.

Climate change and butterflies

23 March 2010

This report appeared in the Statesman on 19 Mar 2010. For the first time, cause-effect relationship between climate change and a living organism has been shown with regards to a butterfly, the Common Brown, Heteronympha merope in Melbourne.

Common Brown (Heteronympha merope)

Image Credit

Butterfly antennas act like GPS!

17 November 2009

Its very easy for army officers to assume that journeying cross-country is simple. They forget that they are specially trained (in map-reading), specially equipped (with compass, GPS and maps) and there is a huge infrastructure ( of cartographers, satellites, high-quality printing presses, logistics, people to update) behind them!

Butterflies dont have maps or compasses....

Butterflies dont need compasses or maps...

Compare this with a butterfly? What could be the limits of its vision? How can it find its way across continents which are proportionally about a few hundred to thousand times larger? Without consciousness how do they do what they do?

And the only instrument they have for navigation is the sun in the sky!

...or GPS to help them migrate over areas they have never travelled before!

Lepidoptera migration is a great mystery!

Take the Monarch, for instance! This Danaid or Milkweed-family butterfly is universally known for its migration which has been well-documented and researched for over a hundred years. The state butterfly or state insect for eight American states, it is the most popular butterfly in North America.

Here’s a very nice look at the place the Monarch butterfly holds in the hearts of the American people!

Monarch Watch Spring 2009 Open House (on Catherine Sherman’s blog)

 

The Monarch (Danaus plexippus), a relative of India's Common and Plain Tigers, is a well-known migrant.

Wikipedia tells us about the Monarch’s migration that… :-

In North America, Monarch butterflies make massive southward migrations starting in August until the first frost. The northward return migration takes place in the spring. The monarch is the only butterfly that migrates both north and south as the birds do on a regular basis. But no single individual makes the entire round trip. Female monarchs deposit eggs for the next generation during these migrations.

Take the case of the population east of the Rocky Mountains. By the end of October, this population migrates to the sanctuaries of the Mariposa Monarca Biosphere Reserve in the Mexican states of Michoacán and México (the western population overwinters elsewhere).

The length of these journeys exceeds the normal lifespan of most monarchs, which is less than two months for butterflies born in early summer. The last generation of the summer enters into a non-reproductive phase known as diapause and may live seven months or more which enables it to migrate from the United States and over-winter in Mexico.

The generation that overwinters generally does not reproduce until it leaves the overwintering site sometime in February and March. It is thought that the overwinter population of those east of the Rockies may reach as far north as Texas and Oklahoma during the spring migration. It is the second, third and fourth generations that return to their northern locations in the United States and Canada in the spring.

Now,  how can a Monarch keep heading South throughout the day when the sun shifts its position from low on the horizon to its highest point at mid-day and again low in the evening?

As the Sun moves across the sky during the day, the Monarch must continuously adjust its calculations so that it does not waver from its chosen direction – South!.

Scientists have now found the key to the Monarch’s genius. It’s in the antennae!

The antennae of the Monarch play a vital role in navigtion during migration.

Researchers at the University of Massachusetts Medical School held the butterfly wings gently and dipped their antennas in enamel paint. They painted the antennas of one set of Monarch butterflies with black paint (which blocked both light and smell) and the antennas of another set were painted with clear paint (which blocked smell but permitted light).

The Monarchs with clear-painted antennas found their way around while those whose antennas were painted black-painted got lost!

That not only showed the antennas were sensing light for navigating, it also showed that the sense of smell isn’t involved in finding the way, since both paints blocked that ability.

And, since the animals with black paint got lost even though their eyes were able to see light, the researchers concluded the antennas were vital to finding the way.

Butterflies whose antennas were surgically removed also became disoriented.

Now how does this work?

In 2008, scientists of of the University of Massachusetts Medical School discovered that Monarchs have ancestral circadian clock mechanisms in their brain which tell them the relative time of the day. This circadian rhythm is formed by the production of and complex biochemical interaction of cryptochrome proteins, which act as critical components in the circadian clock mechanism. Two cryptochrome proteins, named Cry1 and Cry2 were also thought to connect the clock to the sun compass somehow for successful navigation.

This year, the new ‘antenna-painting’ study by this team proved that this sun compass was located in the antenna. Apparently, the antenna sun-compass gives Monarchs the ability to detect the position of the sun and the direction of polarized light.

Gif showing the great wanderings of the Monarch generations! (click to see the gif in action)

When this information is combined with time information from the circadian clock, monarchs are able to steer a course to the South each day and eventually to find their way from all over North America to the Mexican highlands, where they spend the winter.

Read more about it here and here!

The bacteria that kills only male butterflies!

23 October 2009

If you think the swine flu virus was scary, this one makes it look like a Fairy Godmother! Fortunately it is restricted to arthropods and as such is harmless to humans.

But introductions first.

You, Wolbachia does not recognise as you are NOT an arthropod. For Wolbachia, we’ll let Wikipedia do the talking :-

Wolbachia is a genus of inherited bacteria which infects arthropod species, including a high proportion of insects. It is one of the world’s most common parasitic microbes and is possibly the most common reproductive parasite in the biosphere. One study concludes that more than 16% of neotropical insect species carry this bacterium and as many as 25-70% of all insect species are estimated to be potential hosts.”

Wolbachia inside an insect cell.

Wolbachia inside an insect cell.

Now this is really mindboggling. When you say 25 to 70% of all insect species we mean between 1 million to four million ”species” as per the conservative estimate of Gaston (1991) That means Wolbachia is a potential infectant of literally trillions of organisms.

Wolbachia is everywhere, you can’t get away from it.

But so what, we did not know anything about Wolbachia till right now. Why bother?

Because Wolbachia is an organism which detests males, and, by a variety of means, systematically deprives a population of males.

Now, like all males, I am sensitive about my virility, gonads, maleness or what you will. So I instantly recoiled with horror to learn about this organism which specifically targeted the male sex for elimination, albeit in arthropods.

It all started harmlessly when I chose a post from “Not exactly rocket science” in the Science Blogs RSS feed in my Google Reader.

The post states that Wolbachia has seriously affected populations of Hypolimnas bolina, a Nymphalid butterfly called as the Great Eggfly in India or the Blue Moon elsewhere.

The male Blue Moon or Great Eggfly

In grave danger – the male Blue Moon or Great Eggfly.

Commonly found in India, the Great Eggfly is extant from Madagascar in the west across South and Southeast Asia to parts of Australia, Japan and New Zealand and even remote South Pacific islands such as French Polynesia, Tonga, Samoa and Vanuatu.

The female Great Eggfly, once infected, cannot mate successfully with uninfected males.

The female Great Eggfly, once infected, cannot mate successfully with uninfected males.

It appears that this butterfly has been affected severely by Wolbachia. In some islands, notably the Polynesian islands of Ua Huka and Tahiti, Wolbachia, which was virtually absent in the past, is common now and consequently, male butterflies are extremely rare here.

Wolbachia are present in mature eggs, but not in mature sperm. Hence it can propogate only thrugh females and not males; hence the reason for the bacteria developing violently anti-male attitudes!

Only infected females pass the infection on to their offspring. Wollbachia acts in four different ways –

* Firstly, it kills infected males.
* Secondly, it causes infected males to develop into females or infertile pseudo-females.
* Thirdly, it permits reproduction of infected females without males.
* Lastly, the bacterium causes cytoplasmic incompatibility between infected and non-infected insects. Wolbachia-infected males are unable to successfully reproduce with uninfected females or females infected with another Wolbachia strain.

Of this, I find the fact that enables female butterflies to mate without males extremely interesting! Some scientists have suggested that parthenogenesis may always be attributable to the effects of Wolbachia. Parasitic bacteria like Wolbachia have been noted to induce automictic thelytoky in many insect species with haplodiploid systems. They also cause gamete duplication in unfertilized eggs causing them to develop into female offspring.

An example of a parthenogenic species would be the Trichogramma wasp. This wasp has evolved to procreate without males with the help of Wolbachia. Males are rare in this tiny species of insect, possibly because many have been killed by that very same strain of Wolbachia.

All this has been proven thanks to the fact that hundreds of pinned, preserved and catalogued specimens of Great Eggflies can be found in today’s museums. These are from all over and from the heyday of collecting (before Independence).

Emily Hornett, a biologist at UCLA, asked the question –

“How have the ratios of male butterflies to female ones changed over time?”

Concentrating on specimens from the Pacific islands, she observed a number of cases where males reduced in numbers as time passed. Since the DNA of these specimens was still viable, she invented a test which detected the gene sequence of Wolbachia in the genome of the dead insects. She found a very high increase in Wolbachia infection with corresponding effect on the ratio of males to females. From her research, it was clear that Wolbachia steadily went from island to island decimating the males.

Surprisingly, she also detected Wolbachia-resistance in today’s individuals and also in the past in the Phillipines and Samoa. There was evidence of a full scale drawn-out battle beteen Wolbachia and its hosts. In one case, resistance to Wolbachia developed over a very short period of time. This is of great import to us.

The infection mechanism of Wolachia is being extensively studied with the hope of employing this mechanism to halt another killer disease in India, this time of humans, namely malaria.

It is also used to kill the worms which cause filiarisis (elephantiasis). The worms require highly toxic chemicals to kill but a simple antibiotic will kill the Wolbachia in them and they’ll just die because of that!

So, in every cloud, there’s a silver lining. Wolbachia’s hosts have very short lifespans – so it is possible to study evolution in action by researching Wolbachia. And it may possibly help us solve the malaria problem.

Read more about Wolbachia on cheshire’s and hotbacteria’s blog!