Eastern and western North American monarch butterflies


This June 2014 video is called Monarch butterflies amazing migration to Mexico.

From Emory Health Sciences in the USA:

Butterfly genomics: Monarchs migrate and fly differently, but meet up and mate

A genome-wide comparison of eastern and western monarchs

July 29, 2020

Each year, millions of monarch butterflies migrate across eastern North America to fly from as far north as the U.S.-Canadian border to overwinter in central Mexico — covering as much as 3,000 miles. Meanwhile, on the other side of the Rocky Mountains, western monarchs generally fly 300 miles down to the Pacific Coast to spend the winter in California. It was long believed that the eastern and western monarchs were genetically distinct populations.

A new study, however, confirms that while the eastern and western butterflies fly differently, they are genetically the same. The journal Molecular Ecology published the findings, led by evolutionary biologists at Emory University.

“It was surprising,” says Jaap de Roode, Emory professor of biology and senior author of the study. His lab is one of a handful in the world that studies monarch butterflies.

“You would expect that organisms with different behaviors and ecologies would show some genetic differences,” de Roode says. “But we found that you cannot distinguish genetically between the western and eastern butterflies.”

The current paper builds on previous work by the de Roode lab that found similarities between 11 genetic markers of the eastern and western monarchs, as well as other more limited genetic studies and observational and tracking data.

“This is the first genome-wide comparison of eastern and western monarchs to try to understand their behavioral differences better,” says Venkat Talla, first author of the current study and an Emory post-doctoral fellow in the lab.

Talla analyzed more than 20 million DNA mutations in 43 monarch genomes and found no evidence for genomic differentiation between eastern and western monarchs. Instead, he found identical levels of genetic diversity.

“Our work shows that the eastern and western monarchs are mating together and exchanging genetic material to a much greater extent than was previously realized,” Talla says. “And it adds to the evidence that it is likely differences in their environments that shapes the differences in their patterns of migration.”

Co-author Amanda Pierce, who led the earlier study on 11 genetic markers, launched the project while she was a graduate student in the De Roode Lab.

“Monarch butterflies are so fragile and so lightweight, and yet they are able to travel thousands of miles,” Pierce says. “They are beautiful creatures and a great model system to understand unique, innate behaviors. We know that migration is ingrained in their genetic wiring in some way.”

After monarchs leave their overwintering sites, they fly north and lay eggs. The caterpillars turn into butterflies and then fly further, mating and laying another generation of eggs. The process repeats for several generations until finally, as the days grow shorter and the temperatures cooler, monarchs emerge from their chrysalises and start to fly south. This migratory generation does not expend any energy on breeding or laying eggs, saving it all for the long journey.

“For every butterfly that makes it to California or to Mexico, that’s its first journey there,” Pierce marvels.

Previous work had identified a propensity for the eastern and western monarchs to have slight differences in their wing shapes. For the current paper, the researchers wanted to identify any variations in their flight styles.

They collected eastern monarchs from a migratory stopover site in Saint Marks, Florida, and western monarchs from one of their overwintering sites near Oceano, California. Pierce ran flight trials with the butterflies by tethering them to a mill that restricted their flight patterns to circles with a circumference of about 25 feet. The trials were performed in a laboratory under controlled light and temperature conditions that mimicked overwintering sites. Artificial flowers were arranged around the circumference of the flight mills.

“The idea was to try to give them some semblance of a ‘natural’ environment to help motivate them and to orient them,” Pierce explains.

Butterflies were released unharmed from the flight mills after performing short trials.

The results showed that the eastern monarchs would choose to fly for longer distances while the western monarchs flew shorter distances but with stronger bursts of speed. “The more powerful flight trait of the western monarch is like a sprinter, essentially,” Pierce says, “while the eastern monarchs show a flight trait more like marathoners.”

Pierce has since graduated from Emory and now works as a geneticist for the Environmental Protection Agency in Washington, D.C.

Talla, who specializes in bioinformatics, grew up in India where the rich diversity of wildlife inspired him to become an evolutionary biologist. He moved to Sweden to get his PhD, where he studied the genomics of the European wood white butterfly. Although all wood whites appear identical visually, they are actually three different species.

“One of the big questions I’m interested in answering is how does an individual species wind up becoming multiple species?” Talla says. “I want to understand all the processes involved in that evolution.”

He jumped at the chance to join the De Roode Lab. “Monarchs have always been at the top of my list of butterflies I wanted to study because of their incredible migrations,” Talla says. “They are a fascinating species.”

Last November, he joined de Roode on a lab field trip to the eastern monarch overwintering site, inside and adjacent to the Monarch Butterfly Biosphere Reserve in central Mexico. Tens to hundreds of millions of monarchs blanket the trees and landscape through the winter. “It’s a mind-blowing sight,” Talla says. “It makes you wonder how they all know how to get there.”

Previous tracking and observational studies had shown that at least some western monarchs fly south to Mexico instead of west to California. The full-genome analysis suggests that more than just a few of the western monarchs may be making the trip to Mexico where they mix with the eastern monarchs. And when the butterflies depart Mexico, some may fly west instead of east.

“Evidence from multiple directions is coming together to support the same view,” de Roode says.

The findings may help in the conservation of monarchs. Due to a combination of habitat loss, climate change and lack of nectaring flowers, numbers of both eastern and western monarchs have declined in recent decades, with the western ones showing the most precipitous drop. The U.S. Fish and Wildlife Service is currently considering whether the butterflies need special protections.

“If environmental factors are all that drives the differences between the eastern and western monarchs, it’s possible that we could help the western population by transplanting some of the eastern ones to the west,” de Roode says.

The De Roode lab now plans to investigate what exactly in the environments of the butterflies triggers different expressions of their genes.

The work was funded by Emory University, the National Science Foundation and the National Institutes of Health.

Saving rare British butterflies, how?


This June 2014 video from Britain says about itself:

Duke of Burgundy butterfly

Duke of Burgundy is found mainly in central southern England. Patrick Barkham gives an introduction to this beautiful species.

From the University of York in England:

Agricultural conservation schemes not enough to protect Britain’s rarest butterflies

June 23, 2020

Conservation management around the margins of agriculture fail to protect butterfly species at greatest risk from the intensification of farming, a new study says.

The research, from the University of York, says the subsidised schemes are likely to help common, more mobile grassland species like the Ringlet (Aphantopus hyperantus) or the Meadow brown (Maniola jurtina) but not rarer species like the Duke of Burgundy (Hamearis lucina) or the Dingy skipper (Erynnis tages).

Agri-environment schemes financially reward farmers managing land in ways which aim to reduce the environmental impacts of agriculture. Common options include setting aside small areas of land out of production, including leaving grassland strips at the edges of agricultural fields.

The study examined whether these strips helped support insects including grassland butterfly populations. It used ecological models to look at whether the schemes improved butterfly survival locally and also if set aside land helped species expand their range and move across landscapes. This expansion is important so that species can move in response to climate change.

Katie Threadgill, PhD student from the Department of Biology said: “These kind of set aside schemes help mobile, common butterfly species move across landscapes but they do not help all species.

“The greatest benefits were seen in species which were either highly mobile or which live in high densities. High density species which could travel further were already successful expanders regardless of set-asides although expansion rates were still improved when set-asides were added. Overall, set-aside strips did increase rates of range expansion across landscapes by up to 100% for some species but they did not boost long term butterfly survival locally.

Prof Jane Hill, who co-supervised the project added: “Small-scale set-asides have the potential to improve connectivity, which will help some species move to cope with climate change, and connect up habitat patches for others.”

The study concluded that set-asides are unlikely to benefit low dispersal, low density species which are probably at greatest risk from agricultural intensification.

Katie Threadgill added: “Our results suggest that small set-aside strips alone are not an appropriate solution for preventing extinctions in the long term, but can provide other benefits”

Beautiful butterflies, lecture


This 23 June 2020 video from the Natural History Museum in London, England:

Beautiful Butterflies | Live Talk with NHM Scientist

Butterflies appear in an astonishing variety of colourful and intricate patterns. Join Museum scientist Dr Blanca Huertas as she shares her experience studying these beautiful creatures, discovering new species in the field and in the Museum’s incredible butterfly collections.

Butterfly, hummingbirds at Texas, USA feeders


This video from the USA says about itself:

Butterfly Visits West Texas Feeders Alongside Hummingbirds – June 17, 2020

Enjoy watching a cloudless sulphur butterfly sip nectar from the West Texas hummingbird feeders as hummers hover from port to port.

European butterfly evolution, new research


This video says about itself:

Some old footage of butterflies from Germany and Sweden.

Melitaea athalia, Plebejus idas, Araschnia levana and Cabera pusaria.

From ScienceDaily:

Scientists unravel the evolution and relationships for all European butterflies

June 15, 2020

For the first time, a complete time-calibrated phylogeny for a large group of invertebrates is published for an entire continent.

In a recent research paper in the open-access, peer-reviewed academic journal ZooKeys, a German-Swedish team of scientists provide a diagrammatic hypothesis of the relationships and evolutionary history for all 496 European species of butterflies currently in existence. Their study provides an important tool for evolutionary and ecological research, meant for the use of insect and ecosystem conservation.

In order to analyse the ancestral relationships and history of evolutionary divergence of all European butterflies currently inhabiting the Old continent, the team led by Martin Wiemers — affiliated with both the Senckenberg German Entomological Institute and the Helmholtz Centre for Environmental Research — UFZ, mainly used molecular data from already published sources available from NCBI GenBank, but also contributed many new sequences, some from very local endemics for which no molecular data had previously been available.

Butterflies, the spectacular members of the superfamily Papilionoidea, are seen as an important proponent for nature conservation, as they present an excellent indicator group of species, meaning they are capable of inferring the environmental conditions of a particular habitat. All in all, if the local populations of butterflies are thriving, so is their habitat.

Furthermore, butterflies are pollinating insects, which are of particular importance for the survival of humans. There is no doubt they have every right to be recognised as a flagship invertebrate group for conservation.

In recent times, there has been a steady increase in the molecular data available for research, however, those would have been only used for studies restricted either to a selected subset of species, or to small geographic areas. Even though a complete phylogeny of European butterflies was published in 2019, also co-authored by Wiemers, it was not based on a global backbone phylogeny and, therefore, was also not time-calibrated.

In their paper, Wiemers and his team point out that phylogenies are increasingly used across diverse areas of macroecological research, such as studies on large-scale diversity patterns, disentangling historical and contemporary processes, latitudinal diversity gradients or improving species-area relationships. Therefore, this new phylogeny is supposed to help advance further similar ecological research.

Pesticides threaten monarch butterflies


This 2014 video from the USA says about itself:

Researchers Suggest Monsanto Behind 90 Percent Drop in Monarch Butterfly Population

The monarch butterfly population has been reduced by ninety percent over the past twenty years. In terms related to the human population that’s the equivalent of losing every human in the United States except for those in Florida and Ohio.

Monsanto is now Bayer. Different name, same pesticides.

From the University of Nevada, Reno in the USA:

Milkweed, only food source for monarch caterpillars, ubiquitously contaminated

Harmful pesticides found in Western Monarch breeding ground

June 8, 2020

New evidence identifies 64 pesticide residues in milkweed, the main food for monarch butterflies in the west. Milkweed samples from all of the locations studied in California’s Central Valley were contaminated with pesticides, sometimes at levels harmful to monarchs and other insects.

The study raises alarms for remaining western monarchs, a population already at a precariously small size. Over the last few decades their overwintering numbers have plummeted to less than 1% of the population size than in the 1980s — which is a critically low level.

Monarch toxicity data is only available for four of the 64 pesticides found, and even with this limited data, 32% of the samples contained pesticide levels known to be lethal to monarchs, according to a study released today in Frontiers in Ecology and Evolution.

“We expected to find some pesticides in these plants, but we were rather surprised by the depth and extent of the contamination,” said Matt Forister, a butterfly expert, biology professor at the University of Nevada, Reno and co-author of the paper. “From roadsides, from yards, from wildlife refuges, even from plants bought at stores — doesn’t matter from where — it’s all loaded with chemicals. We have previously suggested that pesticides are involved in the decline of low elevation butterflies in California, but the ubiquity and diversity of pesticides we found in these milkweeds was a surprise.”

Milkweed was chosen as the focus of this study because it the only food source for larval monarch butterflies in the West, and thus critical for their survival.

“We collected leaf samples from milkweed plants throughout the Central Valley and sent them to be screened for pesticides,” Chris Halsch, lead author of the paper and a doctoral student in the University’s Ecology, Evolution, and Conservation Biology program, said. “This study is the first necessary step for understanding what butterflies are actually encountering. Now we can use these data to design experiments to test hypotheses about the relative importance of pesticide use and other stressors such as climate change on local butterflies.”

While this is only a first look at the possible risks these pesticides pose to western monarchs, the findings indicate the troubling reality that key breeding grounds for western monarchs are contaminated with pesticides at harmful levels.

“One might expect to see sad looking, droopy plants that are full of pesticides, but they are all big beautiful looking plants, with the pesticides hiding in plain sight,” Forister, who has been a professor int he University’s College of Science since 2008, said.

Western monarchs are celebrated throughout the western states and especially along the California coast where large congregations overwinter in groves of trees. Population declines also have been documented in the breeding grounds. Areas of inland California, including the Central Valley, offer important monarch breeding habitat throughout the spring and summer, including being the home to the very first spring generation which will continue the migration inland to eventually populate all western states and even southern British Columbia.

Declines in the population of western monarch butterflies have been linked with various stressors, including habitat loss and degradation, pesticide use, and climate change, among others. While pesticide use has been associated with declines, previous studies had not attempted to quantify the residues that butterflies can encounter on the western landscape.

The study’s findings paint a harsh picture for western monarchs, with the 64 different pesticides identified in milkweed. Out of a possible 262 chemicals screened, there was an average of nine types of individual pesticides per sample and as many as 25. Agricultural and retail samples generally had more residues than wildlife refuges and urban areas, but no area was entirely free from contamination. Certain pesticides were present across all landscapes, with five pesticides appearing more than 80% of the time. Chlorantraniliprole, the second most abundant compound, was found at lethal concentrations to Monarchs in 25% of all samples.

Understanding of pesticide toxicity to the monarch is limited, and is based on previously reported lab experiments. Thus we have much to learn about the concentrations encountered in field, but these new results raise concerns nonetheless. While this research focused on monarch toxicity, other pollinators and beneficial insects are also at risk from pesticide contamination throughout the landscape.

“We can all play a role in restoring habitat for monarchs,” said Sarah Hoyle, Pesticide Program Specialist at the Xerces Society for Invertebrate Conservation and coauthor of the paper. “But it is imperative that farmers, land managers and gardeners protect habitat from pesticides if we hope to recover populations of this iconic animal.”

Field work, gathering plant samples, was completed last spring and summer. The lab work was completed by Nicolas Baert from the Department of Entomology and manager of the Chemical Ecology Core Facility at Cornell University. Statistical computations were completed this winter by Forister and colleague James Fordyce from the Department of Ecology and Evolutionary Biology at the University of Tennessee, Knoxville.

How butterflies protect themselves against rain


This 2016 video from Texas in the USA says about itself:

Butterflies Flying in Slow Motion HD – Houston Butterfly Museum

Several species of spectacular butterflies flying and courting in full HD slow motion at the Cockrell Butterfly Museum in Houston. For licensing contact hankschyma@yahoo.com

The Houston Museum of Natural Science and the spectacular Cockrell Butterfly Museum is home to dozens of incredible butterflies of all sizes and vibrant colors. This Slow motion HD video captures their beauty as they gallop through the air in 240 to 480 frames per second.

Music: Sonata Quasi Una Fantasia (aka Moonlight Sonata) Composed by Ludwig van Beethoven. Performed by Pecos Hank on the vibes piano.

Birds like rain after drought. Some butterflies also don’t mind.

From Cornell University in the USA:

Armor on butterfly wings protects against heavy rain

June 9, 2020

An analysis of high-speed raindrops hitting biological surfaces such as feathers, plant leaves and insect wings reveals how these highly water-repelling veneers reduce the water’s impact.

Micro-bumps and a nanoscale wax layer on fragile butterfly wings shatter and spread raindrops to minimize damage.

The study, “How a Raindrop Gets Shattered on Biological Surfaces,” published June 8 in the Proceedings of the National Academy of Sciences.

The research showed how microscale bumps, combined with a nanoscale layer of wax, shatter and spread these drops to protect fragile surfaces from physical damage and hypothermia risk.

There already exists a large market for products that use examples from nature — known as biomimicry — in their design: self-cleaning water-resistant sprays for clothes and shoes, and de-icing coatings on airplane wings. Findings from this study could lead to more such products in the future.

“This is the first study to understand how high-speed raindrops impact these natural hydrophobic surfaces,” said senior author Sunghwan “Sunny” Jung, associate professor of biological and environmental engineering in the College of Agriculture and Life Sciences. The lead author is Seungho Kim, a postdoctoral researcher in Jung’s lab.

Previous studies have looked at water hitting insects and plants at low impacts and have noted the liquid’s cleaning properties. But in nature, raindrops can fall at rates of up to 10 meters per second, so this research examined how raindrops falling at high speeds interact with super-hydrophobic natural surfaces.

Raindrops pose risks, Jung said, because their impact could damage fragile butterfly wings, for example.

“[Getting hit with] raindrops is the most dangerous event for this kind of small animal,” he said, noting the relative weight of a raindrop hitting a butterfly wing would be analogous to a bowling ball falling from the sky on a human.

In the study, the researchers collected samples of leaves, feathers and insects. The latter were acquired from the Cornell University Insect Collection, with the help of co-author Jason Dombroskie, collection manager and director of the Insect Diagnostic Lab.

The researchers placed the samples on a table and released water drops from heights of about two meters, while recording the impact at a few thousand frames per second with a high-speed camera.

In analyzing the film, they found that when a drop hits the surface, it ripples and spreads. A nanoscale wax layer repels the water, while larger microscale bumps on the surface creates holes in the spreading raindrop.

“Consider the micro-bumps as needles,” Jung said. If one dropped a balloon onto these needles, he said, “then this balloon would break into smaller pieces. So the same thing happens as the raindrop hits and spreads.”

This shattering action reduces the amount of time the drop is in contact with the surface, which limits momentum and lowers the impact force on a delicate wing or leaf. It also reduces heat transfer from a cold drop. This is important because the muscles of an insect wing, for example, need to be warm enough to fly.

“If they have a longer time in contact with the cold raindrop, they’re going to lose a lot of heat and they cannot fly very easily,” Jung said, making them vulnerable to predators, for example.

Repelling water as quickly as possible also is important because water is very heavy, making flight in insects and birds difficult and weighing down plant leaves.

“By having these two-tiered structures,” Jung said, “[these organisms] can have a super hydrophobic surface.”

The study was funded by the National Science Foundation and the U.S. Department of Agriculture.