Tag Archives: butterfly

Male butterflies ‘dibs’ their mates with a repulsive odor to ward off other suitors

Heliconius melpomene butterflies mating in captivity in Panama. Credit: Kelsey Byers.

Some butterflies have evolved the ability to produce a chemical in their genitals that they spray right after sex to deter other males from persuing the females they’ve marked. Intriguingly, these same chemicals are produced by a flower to entice butterflies for pollination. So the same chemical can either deter or attract other butterflies, all depending on the context, researchers explained.

This striking mating behavior was recently identified by biologists in a species of tropical butterfly endemic to Panama known as Heliconius melponene. A research team led by Chris Jiggins, a professor at  St John’s College, University of Cambridge, sequenced the butterfly’s genome and mapped the scented chemical compound to find the gene responsible for it.

In doing so, the researchers learned that the gene responsible for producing the powerful anti-aphrodisiac pheromone called ocimene in the genitals of male butterflies is also found in some plants.

“For a long time it was thought insects took the chemical compounds from plants and then used them, but we have shown butterflies can make the chemicals themselves – but with very different intentions. Male butterflies use it to repulse competitors and flowers use the same smell to entice butterflies for pollination,” Dr. Kathy Darragh, lead author of the paper, said in a statement.

Female Heliconius melponene butterflies have few sexual partners compared to other species and can store the sperm to fertilize their eggs over a number of months after a single mating. The males, however, are far less picky and will basically have as many mates as possible. Each time the male mates, he releases ocimene in order to increase the odds he may become the lucky one to fertilize the eggs

But, as discussed, ocimene, a terpene, is also produced by a variety of flowers, serving as a floral attractant to aid pollination. So what makes it act differently in plants, allowing it to produce two opposing reactions — attraction and repulsion — in the same species? “Context is key,” Dr. Darragh says.

“The visual cues the butterflies get will be important – when the scent is detected in the presence of flowers it will be attractive but when it is found on another butterfly it is repulsive to the males,” she added.

According to the researchers, the ocimene-producing gene appeared independently in butterflies and plants, signifying a convergent evolutionary event.

“We are very excited about this opportunity to study the genetics of trait evolution at multiple phylogenetic levels. In Heliconius butterflies, there are other closely-related species pairs which differ in their production of ocimene. We hope to study these other pairs to see whether changes in ocimene production is associated with similar types of genetic changes as found in our current study,” Darragh said.

The findings appeared in the journal PLOS Biology.

Butterfly wings are alive and double as hi-tech sensors

Researchers at Columbia and Harvard University have found that butterfly wings are not simply lifeless membranes. Instead, they are riddled with networks of living cells that act like mechanical and temperature sensors.

This allows butterflies to respond quickly to changes in sunlight, thereby protecting their fragile wings from overheating.

Infrared photographs of butterflies. The brighter the color, the bigger the capability of radiative cooling. Credit: Nanfang Yu and Cheng-Chia Tsai/Columbia Engineering.

“Butterfly wings are essentially vector light-detecting panels by which butterflies can accurately determine the intensity and direction of sunlight, and do this swiftly without using their eyes,” says Nanfang Yu, associate professor of applied physics at Columbia Engineering and co-author of the new study published in Nature Communications.

By carefully removing butterfly wings belonging to various species, and by staining the neurons found within them for better monitoring, the researchers discovered that the interior of the wings is loaded with a network of biological sensors. These living tissues are connected to the insect’s blood or hemolymph circulatory system.

The researchers even discovered a “mini heart” inside the butterfly wings that beats a few dozens of times per minute to facilitate the flow of hemolymph.

“Most of the research on butterfly wings has focused on colors used in signaling between individuals,” said Naomi Pierce, Curator of Lepidoptera at the Museum of Comparative Zoology, Harvard and co-lead author of the new study. “This work shows that we should reconceptualize the butterfly wing as a dynamic, living structure rather than as a relatively inert membrane. Patterns observed on the wing may also be shaped in important ways by the need to modulate temperatures of living parts of the wing.”

The team at Columbia Engineering used infrared hyperspectral imaging to map the temperature distribution over the butterfly wings pixel by pixel. This is the first time that this highly challenging task was performed since the insect’s wings are so delicate and fragile.

Researchers discovered that the nanoscale structures and tissues evenly distribute heat across the butterfly wing, reducing the temperature of living structures (wing vein, scent pads, etc).

Temperature distribution for the wings of three species of Eumaeini butterflies. The gradients show how the living tissue in the butterfly wings (scent patches, pads, and wing veins) are always cooled than the “non-living” areas of the wings. Credit: Nanfang Yu and Cheng-Chia Tsai/Columbia Engineering.

In order to test this hypothesis, the scientists performed experiments in the lab that measured the contributions of several environmental factors on wing temperature. These include sunlight intensity, the ambient temperature of the terrestrial surface and that of the air, the latter serving as an efficient heat sink for the butterfly’s wings. This experiment showed that areas of the butterfly wings that contain living tissue are always relatively cooled than the “lifeless” regions.

Another behavioral experiment conducted on living butterflies from six of the seven known butterfly families showed that the insects use their wings to sense the direction and intensity of sunlight. Because sunlight is the main source of heat, the insects have adapted to respond quickly in order to prevent overheating. For instance, individuals from all species turned their wings within seconds of reaching a trigger temperature of 40 degrees Celsius (104 degrees Fahrenheit).

Nanostructures found in the wing scales could someday serve as inspiration for the design of novel radiative cooling materials for applications that have to cope with excessive heat conditions.

“Each wing of a butterfly is equipped with a few dozen mechanical sensors that provide real-time feedback to enable complex flying patterns,” Yu says. “This is an inspiration for designing the wings of flying machines: perhaps wing design should not be solely based on considerations of flight dynamics, and wings designed as an integrated sensory-mechanical system could enable flying machines to perform better in complex aerodynamic conditions.”

Butterflies are genetically wired to mate with others like them

Male butterflies take a particular liking to females which look just like them, researchers found.

Heliconius melpomene malleti feeding on a Gurania flower. Image credits: Chris Jiggins.

Butterflies are weird creatures — there, I’ve said it. Their very existence is tied to one of the most bizarre processes in the natural world (metamorphosis), they have crazy long tongues, and they evolved at least 55 million years ago — making them much, much older than mankind. They are also beautiful creatures with remarkably colorful wings which have been admired by mankind since the dawn of our civilization.

But, for all our admiration, there’s still much we don’t know about them — particularly at the genetic level. In order to address that, researchers from the University of Cambridge, in collaboration with the Smithsonian Tropical Research Institute in Panama, observed the courtship rituals of two Colombian species of Heliconius  — a colorful and widespread genus commonly known as longwings. The team also sequenced the DNA from nearly 300 butterflies to find out how much of the genome was responsible for their mating behavior. Their results brought forth a few surprises. Professor Chris Jiggins, one of the lead authors on the paper and a Fellow of St John’s College, explains:

“There has previously been lots of research done on finding genes for things like colour patterns on the butterfly wing, but it’s been more difficult to locate the genes that underlie changes in behaviour.

“What we found was surprisingly simple – three regions of the genome explain a lot of their behaviours. There’s a small region of the genome that has some very big effects.”

Heliconius melpomene rosina feeding on a Gurania flower. Image credits: Chris Jiggins

Unlike most butterflies, which use chemical signals to find a mate, Heliconian males use their long-range vision to locate females — which also explains why they have distinctive wing markings. Researchers took advantage of this fact and carried out another experiment, introducing male butterflies of one species to females from both species. They then followed the males, noting their levels of sexual interests towards each of them (yes, for science).

They found that males would most often choose females with similar wing markings — again, a rather surprising fact. Dr. Richard Merrill, one of the authors of the paper, based at Ludwig-Maximilians-Universität, Munich, said:

“It explains why hybrid butterflies are so rare — there is a strong genetic preference for similar partners which mostly stops inter-species breeding. This genetic structure promotes long-term evolution of new species by reducing intermixing with others.”

Researchers also published a second paper on the subject, reporting that although hybrids are very rare, there is a surprisingly large amount of DNA shared between both species, DNA that has been shared through hybridization — ten times more than Neanderthals and humans share, for instance. The reason for this, researchers suspect, is that the lifespan of butterflies is shorter than that of humans, which allows for a much higher number of generations over the same period.

“Over a million years a very small number of hybrids in a generation is enough to significantly reshape the genomes of the these butterflies,” says Simon Martin, another one of the authors.

But despite this genetic mixing, the two species retain different behaviors and have not become blended. The part of the genome that defines the sex of the butterflies is protected from the effects of inter-species mating, but more importantly, their genome is tweaked and shaped by natural selection and cultural preferences, which allow species to remain distinct and unique.

Professor Jiggins says that ultimately, this type of study suggests that humans are not as unique as we used to think.

“In terms of behaviour, humans are unique in their capacity for learning and cultural changes but our behaviour is also influenced by our genes. Studies of simpler organisms such as butterflies can shed light on how our own behaviour has evolved. Some of the patterns of gene sharing we see between the butterflies have also been documented in comparisons of the human and Neanderthal genomes, so there is another link to our own evolution,” he concludes.

The two papers have been published in PLoS Biology and are freely available:

Wings

CRISPR was used to change a butterfly’s wing color

Butterflies have complex color and scale patterns that allow them to camouflage, attract mates, or warn predators. Researchers used CRISPR/Cas9 to study the genes of one butterfly species to see how they contribute to the wing color and scale structure. Surprisingly, they found that the scale and color of the wings are linked to the same genes.

Wings

The wings of each melanin gene mutant.
image credits

The squinting bush brown butterfly, Bicyclus anynana, comes from East Africa and is typically a dark brown color. A postdoctoral fellow at the National University of Singapore, Yuji Matsuoka, disabled five of the butterfly’s pigment genes with CRISPR/Cas9. CRISPR is a new gene editing system that is capable of adding and disabling genes to different organisms easily and cheaply. The mutations not only changed the color of the butterfly to a light brown/yellow, but also altered the wing scale structure.

“Our research indicates that the color and structure of wing scales are intimately related because pigment molecules also affect the structure of scales,” says senior author Antónia Monteiro, a biologist at the National University of Singapore’s Faculty of Science and Yale-NUS College in Singapore. “Some end products of the melanin pathway, which produces butterfly wing pigments, play a role in both scale pigmentation and scale morphology.”

One mutation prevented the manifestation of the pigment dopa-melanin and it also caused an extra sheet of chitin to form horizontally on the upper surface of the wing scale. However, when the different pigment dopamine-melanin was mutated, there were suddenly vertical blades of chitin. This work shows that butterfly color and scale structure are intimately linked and seem to work together. These fives genes could constrain the evolution of a butterfly’s color.

The wildtype butterfly (left) and with mutations (right).
Image credits: William H. Piel and Antónia Monteiro.

The morphology of wing scales is very different between butterfly species. Melanin seems to be an important molecule in this process and it is likely not the only one. These results also help us to know more about the development and evolution of butterfly wing scales.

“Some butterflies can have vivid hues just by having simple thin films of chitin on their scales that interfere with incoming light to create shades known as structural colors without producing corresponding pigments,” says Monteiro. “Light beams reflecting off the top and bottom surfaces of the chitin layer can interfere with each other and accentuate specific colors depending on the thickness of the film, so our results might be interesting in this context.”

One interesting application of this result could be to bioengineer bright colors based on butterfly scales in the future. Above all, this discovery helps us to better understand butterfly coloration and wing scale structure.

Journal reference: Matsuoka et al. 2018. Melanin Pathway Genes Regulate Color and Morphology of Butterfly Wing Scales. Cell Reports.

Ecological restoration of moths in the Cretaceous Burmese amber forest. Credit: YANG Dinghua.

Scientists uncover secret color of 200-million-year-old butterfly wings

Ecological restoration of moths in the Cretaceous Burmese amber forest. Credit: YANG Dinghua.

Ecological restoration of moths in the Cretaceous Burmese amber forest. Credit: YANG Dinghua.

Butterflies have fascinated humankind for millennia and have been interpreted in a variety of ways, from omens of love to personifications of the soul. Part of their appeal lies in their wings’ iridescence, where the same principle behind soap bubbles applies — only at a whole new level.

As small as they are, butterfly wings are covered by thousands of microscopic scales, split into two to three layers. Each scale is comprised of multiple layers separated by air. So, what happens is the many equally-spaced layers of the butterfly wing create multiple instances of constructive interference, rather just a single instance from the top to the bottom as is the case in a soap bubble. In some species, such as the morpho butterfly, the resulting effect can be astonishing.

But, unlike pigments, which can survive for millions of years, structural colors are far more difficult to interpret from fossils. Luckily, Chinese researchers at the Nanjing Institute of Geology and Palaeontology, in collaboration with colleagues from Germany and the UK, were able to use novel methods to find that butterflies have been sporting this sort of flashy display for a long, long time.

Wings and scales of Jurassic Lepidoptera and extant Micropterigidae. Credit: ZHANG Qingqing et al.

Wings and scales of Jurassic Lepidoptera and extant Micropterigidae. Credit: ZHANG Qingqing et al.

The team used a combination of advanced imaging techniques on more than 500 ancient butterfly specimens to reveal the wings’ ultrastructures — the architecture of cells visible with magnification. Only six specimens were well preserved enough to be of use, including a 200-million-year-old insect. Most of the butterflies were fossilized in stone, which means their pigment color is gone, but their nanostructure lingered.

By examining the fossilized under an electron microscope, the researchers were able to discern the wings’ pattern: an upper layer of large fused cover scales and a lower layer of small fused ground scales, plus preserved herringbone ornamentation on the cover scale surface. Optical modeling allowed the researchers to infer the structural patterns and characterize the wings’ optical properties.

Tarachoptera from mid-Cretaceous Burmese amber. Credit: ZHANG Qingqing et al.

Tarachoptera from mid-Cretaceous Burmese amber. Credit: ZHANG Qingqing et al.

This analysis suggests that the ancient insect had a color pattern nearly identical to those found on several extant species from the Micropterigidae superfamily — the most primitive extant lineage of Lepidoptera, the insect order that includes butterflies and moths. Optical modeling confirmed that diffraction-related scattering mechanisms of the fossil cover scales would have displayed broadband metallic hues as in numerous extant Micropterigidae, as reported in the journal Science Advances.

Judging from these findings, it seems like the iridescent pattern of wing scales have been an integral part of the Lepidoptera family at least since the Jurassic. Future studies will characterize the optical response of scale nanostructures in other fossil specimens in order to determine the models of the evolution of structural colors in Lepidopterans.

Rare, delicate fossils show butterflies emerged before flowers did

After an unusual set of events, paleontologists have discovered fossil evidence that Lepidoptera — a group of insects which features butterflies and moths — emerged at least 200 million years ago. This contradicts the idea that flowers drove the evolution of butterflies and moths.

The common jezebel butterfly, Delias eucharis. Image in public domain.

Butterflies and rocks

Boston College Research Professor Paul K. Strother was visiting a colleague in Germany. He was also gathering cores from sedimentary rocks, looking especially for vestiges of freshwater algae, but also pollen, spores, pieces of plants and insect legs — anything that could help him recreate the area’s history. Among these samples, he noticed several rather odd-looking flecks of material.

It wasn’t the first time something like this was observed. Paleontologists typically ignore such features, focusing instead on things like pollen or spores, which offer more consistent information. But the specks were abundant in Strother’s  samples, so he analyzed them more carefully. He dissolved the cores in a solvent, preserving only the organic matter. He was able to isolate the strange features but wasn’t able to identify them. Until luck struck, that is.

After about a year, Strother found himself seated next to Torsten Wappler, a University of Bonn scientist who specializes in extinct insects. As it so often happens when social events bring scientists together, a partnership was struck. Strother showed the images to Wappler, who said that it would be possible to identify them, though it wouldn’t be easy. Identifying microorganisms, especially in unusual samples, typically involves a lot of routine, monotonous work. So again, as it so often happens… the two asked an undergraduate to do the brunt of the work. Timo J. B. van Eldijk was up for the task

“Timo is the guy that did all the work,” Strother remembers.

Examples of the oldest wing and body scales of primitive moths from the Schandelah-1 core photographed with transmitted light (magnification 630x). Credit: Bas van de Schootbrugge, Utrecht University.

As it turned out, the features were scales from the wings of moths and butterflies. Using a light microscope, and later a scanning electron microscope, he concluded that they were the wing scales that give butterflies their characteristic, brightly colored aspect. In total, Timo discovered 70 specimens in the 201-million-year-old sample taken from 300 meters below Earth’s surface. But there was even more.

The real shocker

The investigation revealed that there were two types of scales. The first one was the “primitive” one, with a set of scales that was solid all the way down. But there was another discovery: a different type of scales, which was hollow. This was “the real shocker,” researchers say, as it represents modern Lepidoptera, a group of insects which were thought to have a tight evolutionary history with flowers.

As theory has it, this group evolved their proboscises (long and mobile sucking mouthparts) as a response to flowering plants. Plants had nectar, and the insects wanted that nectar, so they adapted in order to better reach it. But the theory, it seems, is wrong. According to the fossil record, plants didn’t develop flowers until 130 million years ago, and this sample is 201 million years old, from the Jurassic.

“The consensus has been that insects followed flowers,” said Strother, a co-author of the paper. “But that would be 50 million years later than what the wings were saying. It was odd to say the least, that there would be butterflies before there were flowers.”

Example of a living representative of a primitive moth belonging to moths that bear a proboscid adapted for sucking up fluids, including nectar. Size of the scale bar is 1 cm. Credit: Hossein Rajaei, Museum für Naturkunde.

During the Jurassic, the dominant group of plants was the gymnosperms, a group which includes conifers such as pine trees — not what you’d expect to find butterflies around. Researchers aren’t exactly sure why insects would have developed proboscises without flowers. The best theory is that they were trying to drink pollen from conifer cones. It could also be that the flower fossil record is missing, or that these elongated mouthparts had another purpose entirely.

Still, it’s not without precedent for one biological part to emerge for one purpose only to later change its purpose completely. The rocks date from a period right around the Triassic–Jurassic extinction event, when numerous creatures went extinct. Butterflies might have taken advantage of this and diversified, filling up all the ecological niches they could. The new research suggests that butterflies are survivors.

Butterflies are survivors. Credits: Momentmal / Pixabay.

Science at its finest

It will take more cores, more samples, and more grunt work before the story of the early Lepidoptera is solved, but this is a great example of classic science: starting not with a plan, but rather with a curiosity. Researchers were intrigued by what they found, and after one thing led to the other, they might have changed the evolutive history of an important group of insects. In my view, modern science needs much more of this.

“This is the old-fashioned science of discovery,” said Strother. “We’re looking at this microscopic world of things that lived hundreds of millions of years ago and we don’t know what they are. The challenge is: can we figure out what they are? Part of it is piecing together the tree of life, or the evolution of organisms through time. It is more like a puzzle or a mystery.”

Journal Reference: Timo J. B. van Eldijk et al. A Triassic-Jurassic window into the evolution of Lepidoptera. DOI: 10.1126/sciadv.1701568.

Schematic describing the CRISPR gene-editing technology used to investigate the key gene that determines butterfly wing patterns. Credit: The George Washington University

Biologists find genetic master switch for the butterfly’s wing color

From eery iridescence to perfect camouflage, butterfly wings are colored in all sorts of intricate patterns. Given their sheer diversity, scientists have always thought that a complex melange of genes code such decorative forms. It turns out, however, that playing around with just two genes is enough to determine the wing’s lines and colors.

modified CRISPR butterfly

The left-hand side shows unmodified wing pattern of Heliconius eratus demophoon butterfly. On the right-hand side, we can see the same butterfly whose WntA gene was knocked out of action. Credit: Smithsonian Tropical Research Institute.

The findings were reported this week in the Proceedings of the National Academy of Sciences journal by an international team of scientists led by Bob Reed, an evolutionary developmental biologist at Cornell University in Ithaca, New York.

The two complementary genes, WntA and optix, were identified after the team altered the genomes of several butterfly species with CRISPR–Cas9 — a powerful gene editing technique which allows scientists to cut and paste DNA sequences. The pair of genes represents ‘adaptive hotspots’ since these code physical changes in the butterfly wings that appear to be adaptations to their environment.

Schematic describing the CRISPR gene-editing technology used to investigate the key gene that determines butterfly wing patterns. Credit: The George Washington University

Schematic describing the CRISPR gene-editing technology used to investigate the key gene that determines butterfly wing patterns. Credit: The George Washington University

Paint-by-number genes

When the genes were switched on and off in various species, among them the famous but gravely endangered monarch butterfly (Danaus plexippus), interesting things happened. Turning off WntA caused the markings and patterns on the wings to fade or disappear altogether. In monarchs, for instance, the trademark dark wing contouring faded to gray.

“Imagine a paint-by-number image of a butterfly,” said Owen McMillan, staff scientist at STRI and co-author, in a press relase. “The instructions for coloring the wing are written in the genetic code. By deleting some of the instructions, we can infer which part says ‘paint the number two’s red’ or ‘paint the number one’s black. Of course, it is a lot more complicated than this because what is actually changing are networks of genes that have a cascading effect on pattern and color.”

While WntA seems to color boundaries and borders, optix acts like a paintbrush that fills in the blanks. For example, when the team switched off this gene in the butterfly gulf fritillary (Agraulis vanillae), their wings turned gray or black instead of the characteristic red and orange color patterns.

Surprisingly, when optix was turned off in the common buckeye (Junonia coenia), its wings became covered in spots of bright, iridescent blue. This signals that the gene is responsible for physical changes beyond pigmentation, since iridescence is determined by tiny microscopic structures on the wing’s scales. This suggests the optix gene “probably played a huge role in wing evolution”, Reed told Nature.

“The butterflies and moths, the Lepidoptera, are the third largest group of organisms known on the planet,” said Arnaud Martin, now Assistant Professor of Biology at George Washington University and corresponding author of the study.

“Once we identified the sets of genes regulated by a gene like WntA, we can look at the sequence of different butterflies in the family tree to see when and where these changes took place during the 60 million years of butterfly evolution.”

Such research serves to provide more insight into butterfly evolution. It’s likely that WntA and optix are part of a wider framework that allowed the insects to constantly morph their appearance according to the environment. One prime adaptation is mimicry, an unusual behavior where animals take on the appearance of another, usually for protection.

“For us who are studying butterflies, which are non-traditional organisms for a laboratory, CRISPR is opening a treasure chest of opportunities we haven’t had before,” Martin told Nature.

Mimicry at its finest — or why this is not a snake

Yes, you read this right, this is not a snake — it’s not even slightly related to a snake. The animal portrayed above has developed a technique called mimicry, evolving in a way to imitate another, usually to protect itself.

The animal above is called Dynastor darius darius, and was first described all the way back in 1775. Dynastor is a genus of butterflies in the Nymphalidae family. Members of the genus can be found from Mexico to Central and South America. It has a very odd appearance for a caterpillar, with a long green body and black, hairy head. Yes, what you thought was a snake is actually a caterpillar — an animal waiting to become a butterfly.

But when it enters its pupal stage (that is, it’s turning from a caterpillar into a butterfly), it puts on a very particular “mask”: it starts looking like a snake, with one of the best animal mimicries I’ve ever seen.

Image via Earth Touch News.

It takes Dynastor thirteen days to become a butterfly, and for that duration, it resembles the head of a Gaboon pit viper — the kind of creature you really don’t want to come across. The butterfly uses mimicry to look like a snake and scare off potential predators, but its disguise wouldn’t be very effective if it remained static. So it actually evolved another trait: it can still sense and react to the world outside through its shell of hardened protein, something unusual for pupae.

“The answer may be that the predator itself turns and flees after suddenly coming face-to-face with a realistic ‘snake’ that waves violently back and forth,” write Annette Aiello and Robert Silberglied in Life History of Dynastor Darius in Panama, “as does the pupa of Dynastor darius when disturbed.”

As mentioned above, this technique is called mimicry, and it’s not restricted to butterflies. Mimicry occurs when a group of organisms, the mimics, evolve to share common perceived characteristics with another group, the models. For caterpillars, evolving this kind of bluff appearance makes a lot of sense, since they’re basically protein just waiting to be picked up by the right predator.
The unusual evolution is driven by the selective action of a signal-receiver or dupe. Mimicry is related to camouflage, in which a species resembles its surroundings or is otherwise difficult to detect, but mimicry isn’t only visual. Though visual mimicry through animal coloration is most obvious to humans, other senses such as olfaction (smell) or hearing may be involved, and more than one type of signal may be employed.
In evolutionary terms, this phenomenon is a form of co-evolution, part of a biological arms race.
Monarch Butterfly.

Death of a dynasty: west North America lost over 95% of its monarch butterflies in 35 years

The end is nigh for the monarch butterfly.

Monarch Butterfly.

Image credits Billings Brett / USFWS.

Tradition dictates that every year, the American West Coast dons a fluttery, black-and-orange coat with the migration of the monarch butterflies (Danaus plexippus). But in recent decades, that coat has become thinner and frailer, an indication that something isn’t quite right with the insects. A decline in their numbers first became evident around the 1980s, and by the 1990s, nature lovers started to report a visible reduction in the swarms of butterflies migrating south for winter.

Now, a team of researchers from the Washington State University warns that we may be witnessing the last migrations of the monarchs, as the species’ numbers have declined to an all-time low.

A sight to behold

Every autumn, the insects make their way from all across the continent to sunnier California, where they spend the winter basking in the sun. Eastern populations of the monarch are known to hop the border into Mexico instead. After the cold months pass, the butterflies make their way back to the US and Canada, sup on spring flowers, lay their eggs on milkweed — and then do it all over again when winter looms.

No matter where they travel to, however, the journey takes D. plexippus over thousands of kilometers of the US countryside, attracting nature lovers everywhere. The butterflies gather in huge numbers and literally cover entire sections of woodland in a riot of black-and-orange wings. The migration is so strikingly beautiful that the event was often caught on film for nature documentaries.

Monarch flood.

Image via Youtube / National Geographic.

Sadly, such footage is the only place you can enjoy the sight today. Back in the 1990s, nature lovers attending the butterflies’ migration were starting to notice that the insects were dwindling in number. This begged the question: what’s happening to the monarchs?

To find out, a team of researchers led by Cheryl Schultz from Washington State University, Vancouver, worked with communities along the coast of California to pool records on butterfly numbers gathered by volunteers from across the state since the 1980s. Because the different groups involved in the migration take various paths — some even overwinter in forest groves west of the Rockies, for example — the team also drew on data gathered by the Xerces Society for Invertebrate Conservation, which recruited volunteers to do a yearly count of the “monarch populations overwintering along the California coast” since 1997.

Royally screwed

They fed this data into a mathematical model designed to dampen the data’s noise — minor fluctuations in numbers caused by the natural year-to-year changes in the pockets of butterflies — to get a good look at the long-term trends of the overall species. Their results paint a very grim future for the monarch: the team reports that their numbers have declined to less than 5% what they were in the mid-1980s, pushing the monarch dangerously close to extinction.

“In the 1980s, 10 million monarchs spent the winter in coastal California,” says lead researcher Cheryl Schultz from Washington State University Vancouver. “Today there are barely 300,000.”

“This study doesn’t just show that there are fewer monarchs now than 35 years ago. It also tells us that, if things stay the same, western monarchs probably won’t be around as we know them in another 35 years,” says Schultz.

Because they looked at population numbers alone, the team can’t offer an answer as to why the butterflies are dying off. It’s likely a ‘death by a thousand cuts’ scenario. Habitat loss and a decline of the summer milkweed which they use to reproduce due to shifting climate and land clearing, along with the effects of harmful pesticides, are wrecking havoc on the insects. More research is required to pinpoint the exact cause, but the findings may come in too late to help save the monarch. A report published by conservation non-profit Center for Biological Diversity concluded that “there is a substantial probability that the eastern monarch butterfly population could decline to such low levels that they face extinction. Researchers estimate that there is between 11 percent and 57 percent probability that the monarch migration could collapse [by 2036].”

The findings we’ve covered here today now show that the western populations of the monarch butterflies are in even more dire shape than the eastern populations, the team notes. Significant conservation efforts are needed to help save the species, and they’re needed sooner rather than later. The US Fish and Wildlife Service is monitoring the situation but is yet to list the monarchs as an endangered species.

The paper “Citizen science monitoring demonstrates dramatic declines of monarch butterflies in western North America” was published in the journal Biological Conservation.

How butterflies have such a beautiful colour

Butterflies are some of the most exquisitely patterned and coloured creatures in the world. The colours all start with the scales on their wings. The scales contain crystals called gyroids that are made of chitin, the substance that is also in insect exoskeletons. These structures are complex and just a few nanometers large — so extremely tiny. Nanotechnology, creating tiny structures for industry, also creates such small-scale structures. They are important in areas such as medicine, electronics, and space travel. However, the nanostructures on butterfly wings are way more complex than anything that can be man-made. A group of researchers examined how the crystals develop on a butterfly’s wing for potential uses in industry.

The small Hairstreak. Image credits: Wilts et al., 2017.

The study that is published in Science Advances set out to discover how these crystals that give butterflies their magnificent colour form. It isn’t yet possible to study a butterfly’s wing while it’s developing, so the researchers examined the scales of a grown butterfly under extreme magnification. The subject? The small Hairstreak butterfly Thecla opisena from Mexico. The upper side is jet-black with blue patches while the lower side is green with a small red patch on the bottom edge of the wing. However, if you zoom into the bright green wing it’s actually not all green. The cover scales are bright green while the background is an orange-red colour. The cover scales themselves are not completely green but are made up of several domains that don’t overlap.

A close-up of one wing scale wing; it has a red background with green domains on top. Image credits: Wilts et al., 2017.

Each scale contains structured nanocrystals that interestingly, were spatially separated and loosely connected to the lower surface of the wing. On the wing, the crystals were arranged in lines, and at the beginning of the line the crystals were really small but as you progress further down the line, the crystals get larger. Perhaps, the scales form this way and are constantly growing on the wing. They seem to be developmental stages frozen in time and show the process of how these crystal form. The way that the scales develop is likely that the casing forms first and then the internal gyroid structure follows.

How the crystals develop over time. Image credits: Wilts et al., 2017.

We do need to keep in mind that this is just one butterfly out of more than 140,000 species. However, it is likely, according to the authors, that this way of development can be generalised to most wing scales and that all butterflies get their colour in a similar way. They could be very useful for nanotechnological applications, such as light-guiding technology because they can manipulate light in arbitrary directions. It is interesting to see how the natural world inspires technological advances.

Journal reference: Wilts, B.D. et al., 2017. Butterfly gyroid nanostructures as a time-frozen glimpse of intracellular membrane development, Science Advances.

Alaskan butterfly may be a rare hybrid

It takes some hardcore survival skills to make it to the frozen wastelands of Alaska – and this butterfly has what it takes. Oeneis tanana, or the Tanana Arctic has the ability to produce antifreeze-like substances in its blood to stave off punishing Alaskan temperatures.

A scattering of tiny white freckles give the Tanana arctic butterfly a “frosted” appearance. Photo by the University of Florida/Andrew Warren

It’s the first species discovered in the state in the past 28 years, and may very well be the only endemic butterfly species to Alaska. It was hiding in plain sight, as researchers have probably seen it before several times, but they didn’t recognize it as a new species because it’s so similar to the Chryxus Arctic species.

The butterfly may have emerged as a hybrid between two other species — a very rare process for animals.

“Hybrid species demonstrate that animals evolved in a way that people haven’t really thought about much before, although the phenomenon is fairly well studied in plants,” said Warren, senior collections manager at the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History on the UF campus. “Scientists who study plants and fish have suggested that unglaciated parts of ancient Alaska known as Beringia, including the strip of land that once connected Asia and what’s now Alaska, served as a refuge where plants and animals waited out the last ice age and then moved eastward or southward from there. This is potentially a supporting piece of evidence for that.”

Furthermore, its evolution may even shed light on Alaska’s geologic past, especially regarding the events that happened during the last glaciation.

“Scientists who study plants and fish have suggested that unglaciated parts of ancient Alaska known as Beringia, including the strip of land that once connected Asia and what’s now Alaska, served as a refuge where plants and animals waited out the last ice age and then moved eastward or southward from there,” Warren explained. “This is potentially a supporting piece of evidence for that.”

However, in order to prove this theory, they first need to conduct genetic studies on the butterfly.

“Once we sequence the genome, we’ll be able to say whether any special traits helped the butterfly survive in harsh environments,” he said. “This study is just the first of what will undoubtedly be many on this cool butterfly.”

For now, Warren wants to return to Alaska, hoping to find out new clues about the butterfly, and perhaps even more species.

“New butterflies are not discovered very often in the U.S. because our fauna is relatively well-known,” Warren said. “There are around 825 species recorded from the U.S. and Canada. But with the complex geography in the western U.S., there are still going to be some surprises.”

Full study here.

Artist's rendering of Oregramma illecebrosa. Image: ichai Malikul

Jurassic insect resembles modern butterfly, though it predates it by 40 million yeras

Discovered in ancient lake deposits in northeastern China and eastern Kazakhstan, this ancient insect looks and exhibits behavior closely mimicking the modern butterfly. The Jurassic age insect  entered the fossil record 165 million years ago, while butterflies as we know them first appeared 80 to 90 million years ago. Though these are set apart by many millions of years, researchers found numerous morphological and ecological features in these two, unrelated clades.

Artist's rendering of Oregramma illecebrosa. Image: ichai Malikul

Artist’s rendering of Oregramma illecebrosa. Image: ichai Malikul

David Dilcher, a Indiana University paleobotanist, along with colleagues   used various cutting-edge techniques ( polarized light and epifluorescence photography, SEM imaging, etc) to study the fossils which belong to the genus kalligrammatid — extinct “lacewings”. Dilcher was involved in the botanic side, and it was soon clear that his experience would prove invaluable in unraveling and tracing the extinct lacewing behaviour.

Dilcher found that the insect, called Oregramma illecebrosa, was covered in microscopic remains of food and polled. He and colleagues concluded that the kalligrammatid must have fed upon an extinct order or seed plants called bennettitales, which first appeared 250 million year ago and survived for a striking 200 million. The insect fed upon the bennettitales using a long tongue to probe the nectar. The pollen would get stuck to both the mouth and hairy legs it possessed. This way the insect must have carried the pollen from the male flower-like reproductive organs of one plant to the female organs of another. This system later was replaced by mid-Cretaceous angiosperms and their insect pollinators, the researchers note in the paper.

The Kalligrammatid fossils clearly exhibit eye spots. Image: Proceeding of Royal Society B

The Kalligrammatid fossils clearly exhibit eye spots. Image: Proceeding of Royal Society B

This is in close association with butterflies, which isn’t enough though to consider the two examples of convergent evolution —  the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Convergent evolution becomes clearer when we consider the fact that the  ancient lacewing fossils’ wings were covered in so-called ‘owl spots’. The texture of the wings resembles big eyes which would fool predators they were in fact face to face with someone who might actually them. The pattern is nearly identical to the modern owl butterfly.

“If it worked once, why not try it again,” said Dilcher commenting upon evolution’s ingenious ways.

 

 

The Hubble Telescope Captures Image of Rare “Cosmic Butterfly”

Hubble has recently captured a dazzling image of a “cosmic butterfly” – the planetary nebula (PN) M2-9. The star has not only ejected its outer layers, but exposed its inner core, which is now illuminating the layers in a spectacular and violent display.

Minkowski's butterfly - Hubble captures spectacular photo of a planetary nebula.

Minkowski’s butterfly – Hubble captures spectacular photo of a planetary nebula.

The M in this name refers to Rudolph Minkowski, the German-American astronomer who discovered this particular nebula in 1947. “Planetary nebula” is technically a misnomer, because the term denotes an expanding glowing shell of ionized gas ejected from an old red giant star (or several). Just 20% of all observed nebulas are spherically symmetric, and a wide variety of shapes exist with some very complex forms seen; this particular one is bipolar – it involves two stars.

The two stars are about the same mass and size as the Sun, ranging from 0.6 to 1.0 solar masses for the smaller star, and from 1.0 to 1.4 solar masses for the other one. The larger star has ejected most of its outer material, while the smaller one has already ejected everything and has evolved into a white dwarf – a stellar remnant composed mostly of very dense electron-degenerate matter. The “wings” are still growing, and it’s estimated that this nebular ejection started about 1,200 years ago – extremely recent in astronomical terms.

Astronomers still aren’t sure if bipolar nebulas emerge from bipolar star systems, or if the two stars somehow got tangled together afterwards. The two seem to circle themselves every 100 years (approximately), and their rotation creates the butterfly wings – actually, very violent jets stripped by the white star from its companion. Recently, the nebula has inflated dramatically due to a fast stellar wind which blew out the surrounding disk and inflated the large, hourglass-shaped wings perpendicular to the disk.

 

Drexel University to Exhibit Half-Male, Half-Female Butterfly

Butterflies are pretty awesome insects – the pupal transformation into a butterfly through metamorphosis is one of the most spectacular processes in the biological world. For one month, until February 16, Drexel University will exhibit a spectacular sample: a butterfly suffering from bilateral gynandromorphism – in other words, a butterfly that is half male, half female.

Image via Drexel University.

The rare butterfly belongs to the Hypolimnas misippus species, or the Danaid Eggfly. The species exhibits a strong sexual dimorphism, with males having different sizes, patterns and colors from females. In October, Chris Johnson, a volunteer at a butterfly display at Drexel University in California and a retired engineer found a member of this species which is split into two halves – one male, and the other female. Its two right wings were of female of its species – big and tan with yellow and white spots. In the mean time, its two left wings donned a darker green, blue and purple shading, a prototype of males.

“It simply gave me goosebumps, it was surprising, something I never anticipated to see,” Johnson said.

The rare condition, bilateral gynandromorphism is not unique, but it’s very rare. Cases of gynandromorphism have also been reported in crustaceans, especially lobsters, sometimes crabs and even in birds. A gynandromorph can have one male half and one female half, or it can be a mosaic – without any clearly delimitated male and female areas.

Lepidopterist and entomology collection supervisor Jason Weintraub of the university said its the first butterfly gynandromorph he’s ever seen.

“It’s thrilling to see because you read about it, and you see specimens in collections, yet when you really see one alive with your eyes, its kind of stunning,” Weintraub included.

 

Metamorphosis

How caterpillars gruesomely transform into butterflies

The caterpillar’s metamorphosis from a tree clinging, 12-legged pest into the majestic flying butterfly is a frequent metaphor for total transformations. It’s truly a fantastic mechanism developed by nature, yet while it may seem fantastic from the outside, this transformation looks pretty gruesome deep inside the chrysalis. In short, for a caterpillar to turn into a butterfly, it digests itself using enzymes triggered by hormones. Then, sleeping cells (similar to stem cells) grow into the body parts of the future butterfly. So you thought puberty was mean? Wait till you read on.

A tough transformation

Metamorphosis

Image: Yahoo

 

Our story begins with a hungry caterpillar who had just hatched from an egg. Soon enough, the little caterpillar (scientifically known as a larva) stuffs itself with leaves, growing little by little. When they’ve outgrown their current skin, a hormone called ecdysone is released, instructing the larva to moult. After it moults about five times, the larva stops feeding, hangs upside down from a twig or leaf, and then either spins itself a silky cocoon or molts into a shiny chrysalis. This process is driven by the same hormone, ecdysone, but this time it works in conjunction with another hormone called the juvenile hormone. It’s actually the lack of the juvenile hormone that triggers the metamorphosis mechanism.

The juvenile hormone acts to delay metamorphosis throughout the whole larva stage.  It works by blocking the genes in the imaginal discstiny disc-shaped bags of cells that kick into action when the caterpillar wraps itself in the chrysalis, eventually turning into an antenna, eye, wing or other butterfly bit. As such, the juvenile hormone is essential to the caterpillar’s survival prior to metamorphosis. You see, once the larva reaches its final moult and begins its metamorphosis, strange things happen to its body. Cells in the larva’s muscles, gut and salivary glands are digested and act as spare parts for the soon-to-be butterfly. Each cell is programmed to self-destruct through the activation of enzymes called caspases.

The caspases tear through the cell’s proteins, releasing prime butterfly-making material. Were it not for the juvenile hormone, this could have happened at any time, killing the caterpillar. Instead, nature programmed the hormone to lower its levels at the ideal moment for metamorphosis. With less juvenile hormone around, instead of inducing a regular moult, the ecdysone now drives the caterpillar to pupate. Once a caterpillar has disintegrated all of its tissues except for the imaginal discs, those discs use the protein-rich soup surrounding them to fuel the rapid cell division required to form the wings, antennae, legs, eyes, genitals and all the other features of an adult butterfly or moth. The imaginal disc for a fruit fly’s wing, for example, might begin with only 50 cells and increase to more than 50,000 cells by the end of metamorphosis.

Metamorphosis isn’t just some beautiful physical transformation, however. It’s a stunning display of evolutionary mechanism at work. Butterflies and caterpillars don’t just look different they behave differently, too. One lives in trees, and the other flies. Most importantly, one eats leaves, and the other solely feeds on nectar. There’s plenty of room for both kinds to coexist in the ecosystem since they don’t interfere with each other’s food stocks. It’s brilliant!

Inside the cocoon

Image: Michael Cook, www.wormspit.com

Image: Michael Cook, www.wormspit.com

Unfortunately, there is little footage that shows metamorphosis at work. The incredible photo pictured above was shot by Michael Cook, who managed to catch this Tussah silkmoth (Antheraea penyi) in a rare position – during a failed attempt to spin its cocoon. You can see the delicate, translucent jade wings, antennae and legs of a pupa that has not yet matured into an adult moth—a glimpse of what usually remains concealed within the cocoon.

Luckily, we live in the 21st century. Using modern imaging tech, like CT scans, we can peek inside the cocoon without disturbing this extremely delicate process. The video below was shot by scientists working at London’s Natural History Museum.

A Giant Blue Morpho butterfly.

Butterfly wings inspire high-tech self-cleaning surfaces

Common to Central and South America, the Blue Morpho is an iconic butterfly, prized for its brilliant blue color and iridescence. Beyond its beauty, however, scientists have discovered that its wings have a certain microscopic texture that could benefit a wide range of applications from self-cleaning instruments, to more efficient piping.

For example, the researchers were able to clean up to 85 percent of dust off a coated plastic surface that mimicked the texture of a butterfly wing, compared to only 70 percent off a flat surface. The Blue Morpho is a highly fragile, light weight insect, so even a few specs of dust or drops of moisture can overburden it and cause a huge energy consumption. Upon inspection by electron microscope, the scientists found that the butterfly’s wings are far from being smooth like they might seem with the naked eye; instead, the surface texture resembles a clapboard roof with rows of overlapping shingles radiating out from the butterfly’s body, suggesting that water and dirt roll off the wings “like water off a roof,” the authors say.  Check out these electron microscope images zoom by zoom.

A Giant Blue Morpho butterfly.

A Giant Blue Morpho butterfly. (c) Ohio State University

Zooming in, texture becomes visible on the wing.

Zooming in, texture becomes visible on the wing. (c) Ohio State University

Wing texture in more detail.

Wing texture in more detail. (c) Ohio State University

Electron microscope image reveals the texture on the micrometer scale.

Electron microscope image reveals the texture on the micrometer scale. (c) Ohio State University

Closeup of micrometer-length 'shingles.' (c) Ohio State University

Closeup of micrometer-length ‘shingles.’ (c) Ohio State University

Nanometer-scale grooves on the surface of the shingles.

Nanometer-scale grooves on the surface of the shingles. (c) Ohio State University

 

“Nature has evolved many surfaces that are self-cleaning or reduce drag,” said Bharat Bhushan, Ohio Eminent Scholar and Howard D. Winbigler Professor ofmechanical engineering at Ohio State. “Reduced drag is desirable for industry, whether you’re trying to move a few drops of blood through a nano-channel or millions of gallons of crude oil through a pipeline. And self-cleaning surfaces would be useful for medical equipment – catheters, or anything that might harbor bacteria.”

In addition to the Blue Morpho, the Ohio State researchers also analyzed leaves of the rice plant Oriza sativa, which also exhibits an interesting self-cleaning texture – rows of micrometer- (millionths of a meter) sized grooves, each covered with even smaller, nanometer- (billionths of a meter) sized bumps; this construction directs raindrops to the stem and down to the base of the plant. Plastic replicas of both microscopic textures were cast and compared in their ability to repel dirt and water to replicas of fish scales, shark skin, and plain flat surfaces.

To test the capabilities of these textures, with respect to other known industry useful texture or simple control texture (smooth), the researchers devised plastic pipes the sized of a cocktail straw with the different coated textures and pushed water through them. The resulting water pressure drop in the pipe was an indication of fluid flow.

A thin lining of shark skin texture coated with nanoparticles reduced water pressure drop by 29 percent compared to the non-coated surface. The coated rice leaf came in second, with 26 percent, and the butterfly wing came in third with around 15 percent.

That was the easy part. Next, the scientists simulated applications where environmental contaminants like dirt are present. So, the dusted each of the textures with  silicon carbide powder, an industrial powder that resembles dirt, and tested them out. They held the samples at a 45-degree angle and dripped water over them from a syringe for two minutes, so that about two tablespoons of water washed over them in total and then, using software, they counted the number of silicon carbide particles on each texture before and after washing.

The shark skin came out the cleanest, with 98 percent of the particles washing off during the test. Next came the rice leaf, with 95 percent, and the butterfly wing with about 85 percent washing off. By comparison, only 70 percent washed off of the flat surface.

The authors believe the rice leaf texture might be especially suited to helping fluid move more efficiently through pipes, such as channels in micro-devices or oil pipelines, while  the Blue Morpho’s clapboard roof texture might suit medical equipment, where it could prevent the growth of bacteria.

Findings were published in the journal Soft Matter.

source

fukushima-butterfly-radiation

Mutant butterflies found near Fukushima linked to radiation exposure

Immediately after the incident at the Fukushima Daiichi nuclear power plant, as a result of the devastating tsunami which swept the country resulting thousands of casualties and damage amount to $40 billion, Japanese authorities quickly evacuated the local human population such that exposure to radiation could be kept at a minimum. The local wildlife, however, wasn’t treated with the same privilege. A month after the tsunami, scientists collected butterfly specimens in the vicinity of the nuclear power plant and found that the insects presented a number of peculiar mutations. Six months later the same check was made for the same species, and findings suggest that the mutations actually multiplied, as an evident effect of radiation exposure.

fukushima-butterfly-radiationSome 144 pale grass blue butterfly were collected, of which 12% of them showed a number of strange mutations, like dented eyes and deformed wings.  When they mated, the offspring showed a mutation rate of 18%, and when one ‘infected’ butterfly was mated with a healthy one, that rate jumped to 34%.This suggested that the butterflies’ germ line, or the cells that turn from egg to sperm, had suffered irremediable damage, which get transmitted to the offspring. Scientists say these mutations will get passed down for many generations.

“Our results are consistent with the previous field studies that showed that butterfly populations are highly sensitive to artificial radionuclide contamination in Chernobyl and Fukushima. Together, the present study indicates that the pale grass blue butterfly is probably one of the best indicator species for radionuclide contamination in Japan,” researchers wrote in the report published in the journal Nature.

The species is notoriously sensitive to environmental contaminants, which is why scientists decided to study them to begin with, so the fact that the pale grass butterfly has suffered mutations isn’t a indicator that other local fauna may have been subjected to the same genetic anomalies, though possible. I’d like to see, personally, a similar research catering to other species, insects or mammals.

The levels of radiation absorbed by the butterflies are not enough to harm humans, however. In fact, Japanese researchers have found very low amounts of radioactivity in the bodies of about 10,000 people who lived near the Fukushima Daiichi power plant when it melted down. The threat appeared to be considerably lower than in the aftermath of the Chernobyl accident, the experts agreed.

“Out of 10,000 people with a dose of 1 millisievert, the radiation would cause two to get cancer during their lifetimes, but about 3,500 would get cancer also without any radiation,” said Roy Shore, chief of research at the Radiation Effects Research Foundation in Hiroshima, Japan. “The jury is still out, but I expect the public health impact from radiation to turn out to be considerably lower than that of Chernobyl.”

via 80 Beats.

Nanostructures off a butterfly wings' surface inspire scientists to design the next generation of accurate and sensitive thermal imaging sensors, which could detect inflamed areas in people, or points of friction in machines. (c) Patrick Landmann/Science Photo Librar

Butterfly wings inspire ultra-sensitive infrared thermal imaging

Butterflies are one of the most enchanting beings in the animal kingdom, a symbol of grace and beauty encountered in every art form. From a crawling larva to a majestic winged creature, it’s difficult not to take notice of the similarities between the butterfly’s metamorphosis process and the ups and downs life serves before one may truly find himself. Before we deviate too far into the metaphysical, however, let’s take a look at what makes a butterfly truly special, namely its wings, and how science has learned to capitalize from them.

Nanostructures off a butterfly wings' surface inspire scientists to design the next generation of accurate and sensitive thermal imaging sensors, which could detect inflamed areas in people, or points of friction in machines. (c) Patrick Landmann/Science Photo Librar

Nanostructures off a butterfly wings' surface inspire scientists to design the next generation of accurate and sensitive thermal imaging sensors, which could detect inflamed areas in people, or points of friction in machines. (c) Patrick Landmann/Science Photo Librar

Butterfly wings, along with a peacock’s feathers, are a perfect example of structural colour display. Typically, butterfly wings contain nanostructured chitin which refracts and reflects light in such manner that it confers them the iridescent colour butterflies are known and treasured for. General Electric chemists, based at the company’s Global Research Center in Niskayuna, New York, seized this opportunity and turned these nanostructures into an infrared (IR) detector, which doesn’t require neither cooling or a heat sink.

The team of researchers lead by Radislav Potyrailo, coated the rows of tiny tree-like structures on scales, taken from a butterfly’s wings, with single walled carbon nanotubes (SWNTs) to absorb more infrared radiation. These allowed the butterfly to absorb even more heat, which caused the nano-structures to expand and in the process, altered the reflected light wavelength.

 ‘The chitin-based material of the Morpho tree nanostructures does absorb over the 3-8µm spectral range [the IR spectrum runs from 0.7-300µm],’ explains Potyrailo

Thermal infrared imaging currently has a myriad of applications, ranging from seeing in the dark (thermal night vision goggles) to sensors that check for insulation, however this kind of equipment is extremely complicated to build and expensive.  The General Electric research infrared detector, just less then a micrometer in size, currently has a resolution 20 times sharper than existing detectors, and because of the chitin’s physical properties and its extremely small scale, it can go from cool to hot extremely fast, making it perfect for applications where fleeting changes in temperature, albeit very small (temperature drops no greater than 0.018 °C may be recorded), need to be constantly monitored.

This doesn’t mean though that we’re going to see any butterfly farms that harvest tons of butterfly wings in the near future, though. What a desolate sight that would’ve been. The GE scientists suggest other materials, such as fluoropolymers and silicones, would be far more suited for manufacturing IR imaging gear, actually outperforming the nanostructures based on the butterfly.

 

“We plan that the infrared light will come from one side of the bio-inspired thin film and will heat up the film,’ he says. ‘The other side of the film will be iridescent and iridescence will locally change its colours upon local heating.’

 

source / image

New Butterfly Species Identified in Mexico’s Yucatan Peninsula

The Nature is a treasure house of wonders. As we go on unlocking its secrets, more remains to be discovered. So is the hunt for finding new butterfly species.

New cryptic species a) Prepona laertesECO01 and b) Prepona laertesECO02, with interim names waiting for full characterization. Dorsal view. Humberto Bahena.

Mexican Scientists, led by Carmen Pozo of El Colegio de la Frontera Sur in Mexico, have claimed to have identified the new species while making a study on the Nymphalidae family of butterflies population in the Yucatan peninsula.

They had reported this in “Beyond the Colours: Discovering Hidden Diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA Barcoding” in the latest online journal PLoS ONE 6(11): e27776.

“Approximately 570 species of Nymphalidae have been reported in Mexico, and 121 of these occur in the Yucatan peninsula. Using DNA bar-coding, which uses the sequence of a standard short gene segment to provide information about biodiversity, they found evidence for several previously undiscovered, so-called ‘cryptic’  species that now await characterization,” the journal reported.

The researchers had also noticed four cases where specimen had been misidentified based on the appearance. They had later corrected these erroneous classifications based on the DNA, highlighting the potential utility of this method.

There are about 160,000 known species of butterflies and moths in the world and scientists believe that a similar number still remains undiscovered.

Identification and characterization of these species is a complex process because each species has an immature caterpillar and a mature butterfly form, as well as the reliance on the physical appearance for classification.

The latest DNA-based bar-coding technique came handy to the scientists for easy identification and characterization of the species.

“This investigation has revealed overlooked species in a well-studied museum collection of Nymphalid butterflies and suggests that there is a substantial incidence of cryptic species that await full characterization.

 

The utility of bar-coding in the rapid identification of caterpillars also promises to accelerate the assembly of information on life histories, a particularly important advance for hyper diverse tropical insect assemblages,” the researchers observed.

Can a butterfly (or moth) remember life as a catterpillar?

butterflyAs you know (or at least should know), butterflies and moths are known for their metamorphosis from catterpillars to their adult form. This radical change involves not just a change of look, but it also includes changes in lifestyle, diet, sensorial impulses and many many other differences. So it would seem very probable that the buttefly has no memory whatsoever of its life in the previous form.

Well, as strange as it would seem, scientists at Georgetown University found out that tobacco hornworm caterpillars could be trained to avoid particular odors delivered in association with a mild shock; and when it emerged from that form, it still avoided the odors, showing larval memory. This is in fact the first study to prove beyond a doubt that associative memory can survive metamorphosis in Lepidoptera.

“The intriguing idea that a caterpillar’s experiences can persist in the adult butterfly or moth captures the imagination, as it challenges a broadly-held view of metamorphosis — that the larva essentially turns to soup and its components are entirely rebuilt as a butterfly,” says senior author Martha Weiss, an associate professor of Biology at Georgetown University.

“Scientists have been interested in whether memory can survive metamorphosis for over a hundred years,” says first author Doug Blackiston.

While most studies around insect memory have focused on social insects, such as honeybees and ants, this particular laboratory focuses on butterflies, praying mantids, and mud-dauber wasps. This sounds quite interesting, but really useless. Well, it’s not! It can actually help scientists identify the signals that are required to direct a cell to develop into a neuron and determining how the complex human central nervous system evolved.