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NEWS RELEASE 29-JUN-2021

DNA barcodes decode the world of soil nematodes

To understand soil ecosystems and contribute to advanced agriculture

TOYOHASHI UNIVERSITY OF TECHNOLOGY (TUT)

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IMAGE: SOIL SAMPLING SITES (TOP). CLASSIFICATION OF SOIL NEMATODE COMMUNITIES BY FEEDING GROUP (RESULTS FOR BARCODE REGION 4) (BOTTOM). view more CREDIT: COPYRIGHT (C) TOYOHASHI UNIVERSITY OF TECHNOLOGY. ALL RIGHTS RESERVED.

Overview

The research team of Professor Toshihiko Eki of the Department of Applied Chemistry and Life Science (and Research Center for Agrotechnology and Biotechnology), Toyohashi University of Technology used a next-generation sequencer to develop a highly efficient method to analyze soil nematodes by using the 18S ribosomal RNA gene regions as DNA barcodes. They successfully used this method to reveal characteristics of nematode communities that inhabit fields, copses, and home gardens. In the future, the target will be expanded to cover all soil-dwelling organisms in agricultural soils, etc., to allow investigations into a soil’s environment and bio-diversity. This is expected to contribute to advanced agriculture.

Details

Similar to when the UN declared 2015 to be the International Year of Soils, there have recently been many efforts worldwide to raise awareness of the importance of the soil that covers our Earth and its conservation. Diverse groups of organisms such as bacteria, fungi, protists, and small soil animals inhabit the soil, and together they form the soil ecosystem. Nematodes are a representative soil animal; they are a few millimeters long and have a shape resembling a worm. They play an important role in the cycling of soil materials. Many soil nematodes are bacteria feeders, but they have a wide variety of feeding habits, such as feeding on fungi, plant parasitism, or being omnivorous. In particular, plant parasitic nematodes often cause devastating damage to crops. Therefore, the classification and identification of nematodes is also important from an agricultural standpoint. However, nematodes are diverse, and there are over 30,000 species. Additionally, because nematodes resemble one another, morphological identification of nematodes is difficult for anyone but experts.

The research team focused on “DNA barcoding” to identify the species based on their unique nucleotide sequences of a barcode gene, and they established a method using a next-generation sequencer that can decode huge numbers of nucleotide sequences. They used this to analyze nematode communities from different soil environments. Initially, four DNA barcode regions were set for the 18S ribosomal RNA genes shared by eukaryotes. The soil nematodes used for analysis were isolated from an uncultivated field, a copse, and a home garden growing zucchini. The PCR was used to amplify the four gene fragments from the DNA of the nematodes and determine the nucleotide sequences. Additionally, the nematode-derived sequence variants (SVs) representing independent nematode species were identified, and after taxonomical classification and analysis of the SVs, it was revealed that plant parasitizing nematodes were abundant in the copse soil and bacteria feeders were abundant in the soil from the home garden. It was also determined that predatory nematodes and omnivorous nematodes were abundant in the uncultivated field, in addition to bacteria feeders.

This DNA barcoding method using a next-generation sequencer is widely used for the analysis of intestinal microbiota, etc., but analyses of eukaryotes such as nematodes are still in the research stage. This research provides an example of its usefulness for the taxonomic profiling of soil nematodes.

Development Background

Research team leader Toshihiko Eki stated, “Through genetic research, I have been working with nematodes (mainly C. elegans) for around 20 years. As a member of our university’s Research Center for Agrotechnology and Biotechnology, I came up with this theme while considering research that we could perform that is related to agriculture. As a test, we isolated nematodes from the university’s soybean field and unmanaged flowerbed and analyzed the DNA barcode for each nematode. Bacteria feeders were abundant in the soybean field, and that was used for comparison with the flowerbed, where weed-parasitizing nematodes and their predator nematodes were abundant. This discovery was the start of our research (Morise et al., PLoS ONE, 2012). If that method using one-by-one DNA sequencing was the first generation, the current method using the next-generation sequencer is the second generation, and we were able to clarify characteristics of nematode communities representing the three ecologically different soil environments according to expectations.”

Future Outlook

Currently, the research team is developing the third-generation DNA barcoding method which involves purifying DNA directly from the soil and analyzing the organisms in the whole soil instead of isolating and analyzing any particular soil-dwelling organisms. They are currently analyzing the soil biota of cabbage fields, etc. They are aiming to precisely analyze how communities of soil-dwelling organisms including microbes change with crop growth, clarify the effects that cultivated plants have on these organisms, and investigate biota closely related to plant diseases. If this research moves forward, crops can be cultivated and managed logically based on biological data in agricultural soils, and it can contribute to advancing smart agriculture in Japan, such as in the prominent Higashi-Mikawa agriculture region and beyond.

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This research was performed with the support of the Takahashi Industrial and Economic Research Foundation.

Reference

Harutaro Kenmotsu, Masahiro Ishikawa, Tomokazu Nitta, Yuu Hirose and Toshihiko Eki (2021). Distinct community structures of soil nematodes from three ecologically different sites revealed by high-throughput amplicon sequencing of four 18S ribosomal RNA gene regions.
PLoS ONE, 16(4): e0249571.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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Sharp Size Reduction in Dinosaurs That Changed Diet to Termites

University of Bristol

5-Jul-2021 4:05 AM EDT, by University of Bristol1favorite_border

Newswise: Sharp Size Reduction in Dinosaurs That Changed Diet to Termites

Zhixin Han/ https://www.artstation.com/xinyanjun

Painting: Artistic reconstruction of four representative alvarezsauroids, Haplocheirus sollers (left), Patagonykus puertai (upper middle), Linhenykus monodactylus (lower middle) and Bannykus wulatensis (lower right), illustrating the body size and dieting change in alvarezsauroid dinosaurs.PreviousNext

Newswise — Dinosaurs were generally huge, but a new study of the unusual alvarezsaurs show that they reduced in size about 100 million years ago when they became specialised ant-eaters.

The new work is led by Zichuan Qin, a PhD student at the University of Bristol and Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. He measured body sizes of dozens of specimens and showed that they ranged in size from 10–70 kg, the size of a large turkey to a small ostrich, for most of their existence and then plummeted rapidly to chicken-sized animals at the same time as they adopted a remarkable new diet: ant-eating.

The alvarezsaurs lived from the Late Jurassic to Late Cretaceous (160 to 70 million years ago) in many parts of the world, including China, Mongolia, and South America. They were slender, two-legged predators for most of their time on Earth, pursuing lizards, early mammals, and baby dinosaurs as their diet.

“Perhaps competition with other dinosaurs intensified through the Cretaceous,” says Prof Michael Benton, one of Zichuan’s supervisors, at Bristol’s School of Earth Sciences. “The Cretaceous was a time of rapidly evolving ecosystems and the biggest change was the gradual takeover by flowering plants. Flowering plants changed the nature of the landscape completely, and yet dinosaurs mostly did not feed on these new plants. But they led to an explosion of new types of insects, including ants and termites.”

This restructuring of ecosystems has been called the Cretaceous Terrestrial Revolution, marking the time when modern-style forests and woodlands emerged, with diverse plants and animals, including insects that specialised to pollinate the new flowers and to feed on their leaves, petals and nectar.

A key problem with many alvarezsaur specimens, especially the chicken-sized ones, was to be sure they were all adults. “Some of the skeletons clearly came from juveniles,” says Dr Qi Zhao, a co-author and an expert on bone histology, “and we could tell this from sections through the bone. These showed the ages of the dinosaurs when they died, depending on the number of growth rings in the bone. We were able to identify that some specimens came from babies and juveniles and so we left them out of the calculations.”

Ant-eating might seem an amazing diet for dinosaurs. “This was suggested years ago when the arms of Mononykus were reported from Mongolia,” says Professor James Clark in Washington, DC, a co-author of this paper, and also one of the first discoverers of tiny alvarezsaurs from Mongolia. “Mononykus was one of the small alvarezsaurs, just about 1 metre long, but probably weighing 4–5 kilograms, a decent-sized Christmas turkey. Its arm was short and stout and it had lost all but one of its fingers which was modified as a short spike. It looked like a punchy little arm, no good for grabbing things, but ideal for punching a hole in the side of a termite mound.”

“Interestingly, alvarezsaur dinosaurs were indeed not small in size or ant eaters at start,” says Professor Jonah Choiniere in South Africa, a co-author of this paper, who was first to report the earliest alvarezsaurs in China. “Their ancestors, like Haplocheirus, are relatively large, close to the size of a small ostrich, and their sharp teeth, flexible forelimbs and big eyes suggest they had a mixed diet.”

Zichuan Qin took all the measurements of body size and mapped these across a dated evolutionary tree of the alvarezsaurs. “My calculations show how body sizes went up and down for the first 90 million years they existed, ranging from turkey to ostrich-sized, and averaging 30–40 kg,” says Zichuan. “Then, 95 million years ago, their body size suddenly dropped to 5 kg, and their claw shapes changed from grabbing and cutting to punching.”

“This is a very strange result, but it seems to be true,” says Professor Xing Xu, a co-supervisor to Zichuan in Beijing. “All other dinosaurs were getting bigger and bigger, but one group of flesh-eaters miniaturized, and this was associated with living in trees and flying. They eventually became birds. We’ve identified a second miniaturization event – but it wasn’t for flight, but to accommodate a completely new diet, switching from flesh to termites.”

The paper

‘Growth and miniaturization among alvarezsauroid dinosaurs’ by Zichuan Qin, Qi Zhao, Jonah N. Choiniere, James M. Clark, Michael J. Benton and Xing Xu. Current Biology

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Click Here for Japanese Translation

French ‘bug farm’ thrives on demand for pesticide-free fruit

昆虫ファームが無農薬トマトを後押し フランス

Farmers in western France are doubling down on an unusual crop: breeding millions of tiny predatory bugs and wasps to protect tomato plants without resorting to the insecticides that consumers are shunning.
Here, we’re in one of the greenhouses for a bug that’s called the macrolophus, says Pierre-Yves Jestin, as clouds of the pale green insects swarm around his hands.
Jestin is president of Saveol, the Brittany cooperative that is France’s largest tomato producer, cranking out 74,000 tons a year.
For several years the cooperative has promoted pesticide-free harvests in response to growing concerns about the impact of harsh chemicals on humans and the environment.
It does so thanks to its own bug farm, launched in 1983, that now stretches across 4,500 square metres (just over one acre) outside Brest, where the tip of Brittany juts out into the Atlantic.
Plans are in the works to add 1,200 square metres more this year, producing macrolophus as well as tiny wasps that feed on common tomato pests such as whiteflies and aphids.
Every week the insects are packed up in plastic boxes and shipped to the cooperative’s 126 growers.
This new extension will allow us to increase our breeding of macrolophus, which are increasingly in demand for the pesticide-free range, said Roselyne Souriau, head of the insect programme at Saveol — whose name means ‘sunrise’ in the local Breton language.
At the same time, it will let us develop a new range — at least we hope — better suited to strawberries, with parasitic micro-wasps that feed on aphids, she said.
– ‘A third way’ –
Because the vast majority of Brittany’s tomatoes are grown in greenhouses, they do not qualify for an organic label, which requires plants to be grown under natural conditions in the ground.
That prompted Saveol to team up with two other Brittany cooperatives, Sica and Solarenn, two years ago to promote their pesticide-free offerings.
In 2020, we didn’t use any chemical treatments at all, said Francois Pouliquen, whose eight hectares at the Saveur d’Iroise farm are part of the Saveol network.
Consumers are now looking to eat healthily, he said. Organic produce exists of course, but it isn’t always within reach for people on a budget.
Pesticide-free is an alternative, a third way, for mass production that is still healthy, he said.
Overall, use of predatory insects by French farmers has soared, with regulators approving 330 species as plant pest treatments in the first quarter of this year, up from 257 in 2015, according to the agriculture ministry.
At Saveol’s insect farm, the predatory bugs feast on moth eggs spread over hundreds of tobacco plants, which are in the same family as tomatoes and eggplants.
The broad leaves make it easy when workers cut the tops off the plants and shake the insects into a giant metal funnel for packing.
Some 10 million macrolophus and 130 million micro-wasps are produced each year, and Saveol claims it is the only growers’ cooperative in Europe with its own insect-raising facility.

AFP-JIJI PRESS NEWS JOURNAL

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Colonialism in Entomology: How a Historical Problem Persists Today

ENTOMOLOGY TODAY

Historical and ongoing practices by scientists in the Global North have extracted scientific knowledge and resources from communities in the Global South, leaving scientists there at a great disadvantage to pursue their work—and their valuable perspectives absent from professional scientific discourse. Gavin Campbell is a Ph.D. student in ecology at the University of West Indies, in Kingston, Jamaica and is among entomologists working to raise awareness of how colonialism impacts entomology and the actions that could work to more equitably distribute access to insect science.

By Gavin Campbell, Rhema Uche-Dike, Kehinde Kemabonta, Ph.D., Sylvester Ogbogu, Ph.D., and Jessica Ware, Ph.D.

Colonialism in Entomology: A Historical Perspective

Entomology is an ancient discipline. Humans globally have been exploiting insects for food over millennia and have interacted with insects at different capacities (e.g., as pests or as items of beauty). People interacting with local biodiversity has led to rich, focused indigenous knowledge on shifting ranges, insect behaviour, and biodiversity. (See, for example, Enawene-Nawe tribal knowledge of stingless beesBlack American sharecropper knowledge of insect pest management, or Aboriginal Australian use of insects for food and medicine).

Despite this rich history of global entomological pursuits, “professional entomology” is often considered to be a field that began with European scientists interested in insects. Linnaeus described many insects in the 10th edition of Systema Naturae  in 1758 and Reverend William Kirby FRS FLS, who is often considered the “father” of entomology, published the first popular English language entomology book, Introduction to Entomology, which was first published in 1815.

As European colonies were “settled,” European entomologists documented the insects present in these locations that were new to them, often ignoring existing knowledge about species held by indigenous people. Further, during the colonial period, many European scientists traveled to the Global South to collect specimens and natural history data. Natural history museums are rich with samples from expeditions to collect examples of the diversity from such regions, like the Archbold expeditions (funded by the wealthy father of American Richard Archbold), which sampled Madagascar (1929-1931) and the Philippines in the 1930s. This practice often resulted in great numbers of species being described, with types deposited in museums north of the equator.

More broadly, colonial powers gained wealth, enriched by the exploitation of land and labour in their colonies. Colonized regions, meanwhile, often remained impoverished, as wealth was inequitably distributed; funds flowed to the colonizers, leaving native and formerly enslaved people disenfranchised and often violently prevented from accumulating wealth (e.g., the Tulsa massacre, USA, 1921). Countries that fought for freedom and independence, like Haiti, were saddled with debt: France required Haiti to pay a debt of 150 million francs in 1825 to be declared a sovereign republic. This was ostensibly to pay France back for income lost when enslaved people were freed; it proved to be an insurmountable burden for generations to come.

In North America, Europe, Australia and New Zealand, economic inequalities grew after the emancipation of enslaved and indigenous people, and systemic practices privileged descendants of colonizers for education and jobs. Racialization and minoritization of Americans who are Black, indigenous, or persons of color, for example, led to inequitable education systems, extreme economic divisions, and barriers to participation in decision-making processes.

Gavin Campbell
Rhema Uche-Dike

How Does Colonialism Affect Scientific Capacity Building?

As one example, the advent of PCR and Sanger sequencing and the development of computerized tomography techniques for morphological data collection has led to resolution of the evolutionary histories of numerous insect groups, but who has been able to participate in this vital work? As scientific advances were made, the knowledge and training in these areas, such as Sanger sequencing genetic techniques, were focused in the regions where they were developed, largely in the Global North. Today, a huge number of specimens and data collected from the Global South are stored in museums and on servers located in the Global North, where they stay almost inaccessible by researchers from the Global South.

Indeed, researchers outside of the United Kingdom, Australia, New Zealand, and North America are often working without access to elite academic networks, without substantial funding, and without high-speed internet. Training and capacity building for new methodologies and techniques have largely remained in the Global North, with resources for these techniques greatly limited and even unavailable in the Global South, leading to a skewed general belief that “expert knowledge” can only be found in the Global North.

It is current practice for entomologists studying systematics to travel to the Global South, where the bulk of insect diversity is found, and collect specimens; however, most processing, description, analyzing, and publishing takes place in the Global North, with scientists from the biodiversity hotspot regions at a serious disadvantage for working on these taxa due to historical and current inequities in resource distribution. Whereas the Global North is equipped with the information and resources to best understand and protect local ecosystems, such information is lacking in the Global South. Development decisions in the Global South thus may risk the loss of native species and ecosystem services. Meanwhile, to compete with international researchers, many of the scientists in the Global South migrate to the Global North, further enriching the North and depriving the Global South.

How Does Colonialism Affect the Content of Insect Science?

The history of colonialism has led to inequities in access and capacity building, but it also has limited how we conduct our science. Researchers from the Global South wishing to study the biodiversity of their local taxa, for example, often struggle to get access to type material located in museums in the Global North. Scientists from the Global North far too often continue to lead field expeditions in tropical locations, for example, without including local collaborators and indigenous scientists in either onsite work or ensuing publication.

Further, much of the framing of science has been done from a Northern perspective. As entomology has been centered in the Global North, the majority of information on insects addresses northern conditions with little to no mention of conditions in the Global South such as weather and seasons. It is commonplace to see references of insects overwintering in different stages, changing behaviour (migration), or altering community assemblages in response to a cold winter. However, seasons in the tropics are more structured by rainfall rather than significant changes in temperature, and yet information on insect dynamics in relation to wet and dry seasons is limited, hindering understanding the dynamics of these tropical ecosystems.

General trends (e.g., tropics warmer) are insufficient in accurately quantifying parameters of insects such as life history, number of generations annually, dispersal, competition, fecundity, pathology, and more. As the tropics experience dry and wet seasons annually, understanding of the adaptations of species to these conditions can provide means of adapting societies and ecosystems to the intensified effects of climate change.

Where Do We Go From Here?

What does this mean for entomology? Colonialism has set up a system where entomologists in the Global North are rewarded for work on cutting-edge, often expensive projects.  Entomologists from the Global South are working with limited access to resources such as genomic sequencing, CT scanning, and museum collections due to historical and present-day inequities. Northern hemisphere collections house invaluable specimens, but these are largely inaccessible to researchers living outside of the Global North. What can we do to equitably address colonialist history in entomology? There is lots of work to be done, but to start we suggest:

  1. Digitize specimens and label information in our collections; make these data publicly accessible.
  2. Reassess and change rubrics for graduate admissions, research awards, and student competitions that have too often favoured expensive and exclusive methods; such rubrics are biased against scientists from the Global South.
  3. Increase collaborative networks to build true partnerships when doing field work; consequently, acknowledgement should be accorded where due.
  4. Assess language and writing for biased content that frames research in terms of the northern and western hemispheres.
  5. Educate yourself and your lab about the history of colonialism and its impacts on science.

Diversifying entomology and addressing historical and neocolonial science practices will take time, and the time to join forces to tackle these issues is long overdue. Let’s work together to make systemic change in entomology, biology, and across the sciences.https://www.youtube.com/embed/3iBJdRQiM0s?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent&listType=playlist&list=PLwowbA8nqpC0_6B5N8mUmoI8zwMyyax3V

In February 2021, the authors participated in a panel discussion on scientific colonialism during Black in Entomology Week. For more, see the full playlist of recorded events from Black in Entomology Week.

Gavin Campbell is a Ph.D. student in ecology at the University of West Indies, in Kingston, Jamaica. Rhema Uche-Dike is a research assistant at University of Lagos in Lagos, Nigeria, and an incoming Ph.D. student at The City University of New York in New York, New York, USA. Kehinde Kemabonta, Ph.D., is an associate professor at the University of Lagos, in Lagos, Nigeria. Sylvester Ogbogu, Ph.D., is a professor at Obafemi Awolowo University, in Ile-Ife, Nigeria. Jessica Ware, Ph.D., is associate curator of invertebrate zoology at the American Museum of Natural History, in New York, New York, USA, and current vice president of the Entomological Society of America. Email Jessica Ware at jware@amnh.org.

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NEWS RELEASE 22-JUN-2021

The very venomous caterpillar

Venomous caterpillar has strange biology

UNIVERSITY OF QUEENSLAND

Research NewsSHARE PRINT E-MAILVolume 90% 

VIDEO: THE DORATIFERA VULNERANS IS COMMON TO LARGE PARTS OF QUEENSLAND’S SOUTH-EAST AND SHOWS PROMISE FOR USE IN MEDICINES AND PEST CONTROL, INSTITUTE FOR MOLECULAR BIOSCIENCE RESEARCHERS SAY…. view more 

CREDIT: INSTITUTE FOR MOLECULAR BIOSCIENCE, THE UNIVERSITY OF QUEENSLAND

The venom of a caterpillar, native to South East Queensland, shows promise for use in medicines and pest control, Institute for Molecular Bioscience researchers say.

The Doratifera vulnerans is common to large parts of Queensland’s south-east and is routinely found in Toohey Forest Park on Brisbane’s southside.

Dr Andrew Walker has been researching the striking looking caterpillar since 2017.

“We found one while collecting assassin bugs near Toowoomba and its strange biology and pain-causing venom fascinated me,” Dr Walker said.

Unlike The Very Hungry Caterpillar that charmed generations of children around the world, this caterpillar is far from harmless.

“Its binomial name means ‘bearer of gifts of wounds’,” Dr Walker said.

Dr Walker’s research found the caterpillar has venom toxins with a molecular structure similar to those produced by spiders, wasps, bees and ants.

The research also unlocked a source of bioactive peptides that may have uses in medicine, biotechnology or as scientific tools.

“Many caterpillars produce pain-inducing venoms and have evolved biological defences such as irritative hairs, toxins that render them poisonous to eat, spots that mimic snake eyes or spines that inject liquid venoms,” Dr Walker said.

“Previously researchers had no idea what was in the venom or how they induce pain.

“We found that the venom is mostly peptides and shows stunning complexity, containing 151 different protein-based toxins from 59 different families.”

The researcher team synthesised 13 of the peptide toxins and used them to show the unique evolutionary trajectory the caterpillar followed to produce pain-inducing venom.

“We now know the amino acid sequences, or the blueprints, of each protein-based toxin,” Dr Walker said.

“This will enable us to make the toxins and test them in diverse ways.”

Some peptides already produced in the laboratory as part of Dr Walker’s research showed very high potency, with potential to efficiently kill nematode parasites that are harmful to livestock, as well as disease-causing pathogens.

“Our research unlocks a new source of bioactive peptides that may have use in medicine, through an ability to influence biological processes and promote good health,” he said.

“First, we need to work out what the individual toxins do, to inform us about how they might be used.”

The findings incorporate work from researchers at the CSIRO, Canada’s York University, Austria’s University of Vienna and the Department of Food and Agriculture in the US.

The research is published in the Proceedings of the National Academy of Sciences of the USA.

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Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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New evidence links insect population collapse to dams

by Liam N. Nash, The Conversation

Over 40% of all insects, like this tropical dragonfly, are in decline. Credit: Scottslm/Pixasbay

Insects are the most numerous group of animals on the planet. There are an estimated 5.5 million species, 80% of which remain to be discovered. Yet insects are experiencing steep, widespread declines across the world: a “death by a thousand cuts” because of human activity.

Insects perform almost every role imaginable in an ecosystem, including pollinating crops, keeping pests under control, and acting as food for other animals. The potential consequences of their decline are so dire that it has been dubbed the “insect apocalypse.”

Following the flurry of attention this impending environmental catastrophe generated, a more complex picture has emerged—with one gap in our understanding glaringly clear. Despite tropical and subtropical regions housing an estimated 85% of Earth’s insects, what is happening in those regions is critically understudied.

Dams and declines

Understanding insect decline requires long-term datasets, which are rare, especially from the global south. In our new study, we present one of the most comprehensive known datasets of subtropical freshwater insects, spanning 20 years. What we found were pervasive declines in insect numbers across all examined aquatic insect groups, including midges, mayflies and dragonflies.

Declines occurred in channels, lakes, rivers and backwaters across one of South America’s largest freshwater systems, the Paraná River floodplain. In parallel, we found that numbers of invasive fish increased and water chemistry became more imbalanced—environmental changes all linked to the construction of dams.

<img src="https://scx1.b-cdn.net/csz/news/800a/2021/new-evidence-links-ins-1.jpg&quot; alt="New evidence links insect population collapse to dams" title="Itaipu Dam, on the Paraná River. Credit: <a class="source" href="https://commons.wikimedia.org/wiki/File:Itaipu_geral.jpg">Jonas de Carvalho/Flickr
Itaipu Dam, on the Paraná River. Credit: Jonas de Carvalho/Flickr

At the same time, dams block the flow of sediment and nutrients, disrupting the water chemistry and making the water more transparent. Most aquatic insects are dark or mottled for camouflage in murky water. The increased water transparency weakened their ability to hide, making them even more vulnerable to being eaten by the invading fish.

Around 70% of Brazil’s electricity comes from hydropower, and hydroelectric dams will be essential in the transition away from fossil fuels. Nevertheless, damming can have severe environmental and social impacts. Our study shows that the negative consequences of dams can occur long after the forests have been flooded and local communities dislocated.

Tropical data shortfall

While the tropics and subtropics are the most biodiverse regions on the planet, they are also among the most threatened. Their bountiful natural resources are under immense pressure to provide food, water and energy for some of the planet’s fastest growing human populations and developing economies.

<img src="https://scx1.b-cdn.net/csz/news/800a/2021/new-evidence-links-ins-2.jpg&quot; alt="New evidence links insect population collapse to dams" title="Some flying insects such as midges have aquatic larvae, which fare worse in dammed rivers. Credit: <a class="source" href="https://pixabay.com/photos/chironomid-mosquito-insect-nature-2389699/">Kathy2408/Pixabay
Some flying insects such as midges have aquatic larvae, which fare worse in dammed rivers. Credit: Kathy2408/Pixabay

Despite this, the logistical challenges of studying insects in such a biodiverse region, combined with continued historical inequality around where monitoring is conducted, means that the tropics remain underrepresented in studies on insect decline.

The lack of long-term datasets from the tropics and subtropics can skew the already complicated picture of how insect declines are occurring across the planet. One of the most comprehensive studies to date on global insect decline compared 166 surveys of over ten years across five continents.

It found land-based insects were indeed declining, but water-based insects were on the increase. However, of the 68 freshwater insect datasets in their analysis, only 7% came from the tropics. This apparent success is skewed by an overabundance of studies from Europe and North America, where increasing water quality and effective policies have boosted aquatic insect numbers.

Our results contradict the conclusions of this research. Aquatic insects are on the decline in the Paraná River system, which drains a significant proportion of southern South America -– highlighting the importance of better tropical data. Tropical and subtropical aquatic insects may be more at risk from human activity than their counterparts in more northern regions. Freshwater regions are among the most threatened ecosystems in the world, and must be a target for global conservation efforts.

Successes for aquatic insect conservation in some parts of the world should be celebrated—but without obscuring the challenges elsewhere. Tropical insects are understudied, not unimportant.


Explore further No insect crisis in the Arctic—yet

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How glasswing butterflies grow their invisible wings

By Anil OzaJun. 22, 2021 , 5:45 PM

In a small tent in the middle of Panama’s rainforest, Aaron Pomerantz assembled a makeshift field lab, filled with microscopes, chemical reagents, and delicate lab equipment. At times, it was so hot that Pomerantz, an integrative biologist at the University of California, Berkeley, struggled to keep his own sweat from contaminating his delicate lepidopteran samples. He was looking for something nearly invisible—transparent butterflies known as glasswings.

The rare butterflies “are like ghosts in the rainforest,” says Nipam Patel, Pomerantz’s Ph.D. adviser. Now, Pomerantz and Patel have done more than just find the butterflies—they’ve also solved an enduring mystery: how their wings are transparent in the first place.

The glasswing butterfly (Greta oto), a baseball-size flier that lives throughout Central and South America, is one of hundreds of butterfly species with transparent wings. This rare adaptation helps it evade potential predators. Compared with other see-through species, such as dragonflies, glasswings are even more adept at fluttering through the rainforest unnoticed because their wings don’t shine or glimmer in sunlight.

Patel, who normally studies arthropod evolution, has a lifelong interest in glasswings—and a collection of tens of thousands that he has assembled since the age of 8. To understand what makes the critters so stealthy, Patel, now director of the Marine Biological Laboratory in Woods Hole, Massachusetts, asked a group of graduate students to take microscopic images of the wings of a dozen or so species of transparent butterflies.

His students found that “every way you can think of being transparent, some butterfly or moth has figured out,” Patel says. A butterfly’s wings consist of a thin, membranous layer of a natural polymer called chitin, which is typically covered with tiny scales that resemble interlocking tiles. Species with transparent wings have found ways to move light around these scales, producing fewer of them, turning them vertically, or simply getting rid of them.

The group found that glasswings not only produce fewer scales, but they also convert many of those scales into bristles, allowing light to pass through the wings more easily. Using a scanning electron microscope, Pomerantz also discovered that tiny mounds between the bristles, known as nanopillars, are coated in a layer of wax.

The nanopillars seem to help reduce glare, Pomerantz says. Glare happens when light hits a surface and bounces off at the same angle, as if striking a mirror. The nanopillars “rough up” the surface of the wings and cause the light to bounce off at multiple angles, diffusing the reflection, the researchers wrote last month in the Journal of Experimental Biology. “Because they’re so small, they act kind of like little bitty speed bumps,” Pomerantz says.

In addition, the waxy coating slows down light that passes through the wings because it is more dense than air—like forcing someone to swim through molasses. That reduction in speed softens the impact of light hitting the scales, further reducing glare. Stripping the glasswings of their waxy coating and nanopillars resulted in wings that were shiny, Pomerantz says.

Although many transparent species, including the hand-size hyperiid, have developed these microscopic speed bumps, the wax coating is a new and somewhat puzzling find, says Sonke Johnsen, a biologist at Duke University. That’s because butterflies’ chitin covering is strong—and the addition of the wax layer weakens it. “Why forgo those amazing advantages that you get with chitin to replace it with this wax?” Johnsen asks. “I bet there’s more to the story that they’re going to find out.”

Understanding these antireflective properties could one day help researchers efficiently funnel light into solar panels and create cheaper antiglare lenses for cameras or glasses. But for now, Pomerantz and Patel want to focus on how glasswings evolved from nontransparent ancestors, using genomics to identify the key genes.

“It’s just fascinating to know how nature solves really interesting problems like this,” Patel said. “You can pay extra for glasses that have an antireflective coating on them. But, of course, essentially, butterflies figured that out maybe tens of millions of years ago.”Posted in: 

doi:10.1126/science.abk1168

Anil Oza

Anil Oza

Anil Oza is a Diverse Voices in Science Journalism intern for the News section of Science. 

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132,210 square meters

Zhejiang University opens 11 research greenhouses

A research greenhouse has been completed in Zhejiang University’s Agricultural Science and Technology Innovation Experimental Center, China. This research greenhouse designed and built by Kingpeng has a total area of ​​132,210 square meters, including an artificial climate room, teaching display greenhouse, glass and net greenhouse room, insect control net greenhouse, and various experimental greenhouses. In total, there are 11 single greenhouses and 137 growing rooms.

“Each greenhouse integrates automatic control system which also includes fire protection monitoring and access control monitoring systems,” the Kingpeng team shows. “It can accurately monitor and adjust the internal environment of the greenhouse through various forms such as computers and mobile phones. Independently control of equipment in each room is possible.”

The control system will collect climate data of each room, these data will be categorized and analyzed for further study.

137 separate rooms have been built for different experiments. Not only a general glass greenhouse but also net houses, plant factories, and artificial climate rooms, etc. have been built for different experiment requests.

“In each room, there are also different cultivation systems used for different crops. This is to make more possibility on a multivariate experiment during agriculture study” said a Professor of The Rural Development Academy Zhejiang University.

This research center is put into use in June and is currently the most advanced agricultural facility experimental zone in China and we believe it will become the most advanced support for agriculture-related research in the future!

For more information:
Beijing Kingpeng International Agriculture Corporation
7th floor, Advanced Material Building, Feng Hui Zhong Lu, Haidian District,
Beijing, China, 100094
T: +8658711536
F: +8658711560
info@chinakingpeng.com
www.kingpengintl.com 

Publication date: Thu 24 Jun 2021

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Bt Cotton adoption in Punjab has resulted in net economic, environmental benefits: Study

Vikas VasudevaCHANDIGARH, JUNE 21, 2021 19:34 ISTUPDATED: JUNE 22, 2021 15:52 IST

Yields have stabilised after its commercialisation, says expert

Amid the perpetual debate surrounding Bt cotton’s positive and negative impacts, a recent study titled — ‘Long-term impact of Bt cotton: An empirical evidence from North India’ — has said its adoption in Punjab in the past over a decade has resulted in net economic and environmental benefits.

Also read: Comment | The flawed spin to India’s cotton story

The research was funded by the Agricultural Extension Division of the Indian Council of Agricultural Research under extramural project “Impact evaluation of integrated pest management technologies”. The study was jointly done by the Punjab Agricultural University at Ludhiana, the Sher-e-Kashmir University of Agricultural Sciences and Technology in Jammu (SKUAST) and the Noida-based Amity University, and has been recently published in the Journal of Cleaner Production Elsevier.

“Since the commercialisation of Bt cotton, there has been reduction in insecticide use by volume and applications, decline in environmental and human health impact associated with insecticide use, more so with the reduction in the use of highly hazardous and riskiest insecticides, and reduction in the expenses associated with insecticide use. Also, cotton yields in the past 13 years have been stable, the only exception being 2015. Yet over the past 13 years, pesticide use has gradually increased in Bt hybrids and reduced in non-Bt varieties, primarily driven by the use of fungicide, which was not applied in cotton in 2003 and 2004.

“Akin to the discovery of synthetic pesticides in the 1940s, which was proclaimed as ‘silver bullet technology’ by entomologists, the complete reliance on Bt cotton without incorporating it into the integrated pest management (IPM) system led to outbreak of whitefly in northern India and pink bollworm in western India in 2015; thus, resistance to Bt cotton is yet to become a significant problem. Compatibility of Bt with IPM is not a given when we have weaker institutional setting with ad hoc IPM system and the contrarian view that Bt cotton has been a failure in India, in this case Punjab, lacks empirical evidence,” professor Rajinder Peshin of SKUAST told The Hindu.

Bt (Bacillus thuringiensis) cotton has been commercially grown in India for the past 19 years. The Genetic Engineering Approval Committee (GEAC) approved the release of Bt cotton for commercial cultivation in 2002 in western and southern parts of the country. In Punjab, Bt cotton was released for cultivation in 2005. Before the release, it was adopted by 72% farmers on 22% of the cotton area. However, a lot of questions have been raised recently on its impact.

“To find out the long-term socio-economic and environmental impacts of Bt cotton cultivation on cleaner production, we revisited cotton growers surveyed in 2003 and 2004 again in 2016-17. Before-after, with-without, and difference-in-differences [with and without sample attrition] within farm comparisons were analysed to find the impact of Bt cotton over time. Our results show that sucking insect pests have replaced bollworms as the key pests.

Decline in insecticide applications

“There has been a steep decline in insecticide applications to control bollworms, the target pest of Bt cotton, by 97%; however, this has been offset by an increase in the insecticide application by 154% to control sucking pests. Moreover, the increase in pesticide use was driven by the use of fungicides, which were not applied in cotton earlier, and increased use of herbicides.

“Our results show overall positive impact of Bt cotton on volume of insecticide active ingredients (a.i.) applied, insecticide applications, use of highly hazardous and riskiest insecticides, and resultant environmental impact of the field use of insecticides on cotton. Yields have stabilised after the commercialisation of Bt cotton,” said Mr. Peshin.


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The Humidity of Flowers Acts As An Invisible Attractor For Bumblebees

University of Bristol

22-Jun-2021 6:05 AM EDT, by University of Bristolfavorite_border

Newswise — As well as bright colours and subtle scents, flowers possess many invisible ways of attracting their pollinators, and a new study shows that bumblebees may use the humidity of a flower to tell them about the presence of nectar, according to scientists at the Universities of Bristol and Exeter.

This new research has shown that bumblebees are able to accurately detect and choose between flowers that have different levels of humidity next to the surface of the flower.

The study, published this week in the Journal of Experimental Biology, showed that bees could be trained to differentiate between two types of artificial flower with different levels of humidity, if only one of the types of flower provided the bee with a reward of sugar water.

To make sure that the artificial flowers mimicked the humidity patterns seen in real flowers, the researchers built a robotic sensor that was able to accurately measure the shape of the humidity patterning.

Dr Michael Harrap carried out the research whilst based at the University of Bristol’s School of Biological Sciences and is lead author of the study. He said: “We know that different species of plants produce flowers that have distinct patterns of humidity, which differ from the surrounding air. Knowing that bees might use these patterns to help them find food shows that flowers have evolved a huge variety of different ways of attracting pollinators, that make use of all the pollinators’ senses.”

Professor Natalie Hempel de Ibarra, Associate Professor at the University of Exeter’s School of Psychology, explained: “Our study shows that bumblebees not only use this sensory information to make choices about how they behave, but are also capable of learning to distinguish between humidity patterns in a similar way to how they learn to recognise the colour or smell of a flower.”

Dr Sean Rands, Senior Lecturer in the University of Bristol’s School of Biological Sciences, added: “If humidity patterns are important for attracting pollinators, they are likely to be one of several different signals (such as colour, scent and pattern) that a flower is using at the same time, and could help the bee to identify and handle the flower more efficiently.

“The effectiveness of humidity patterns may depend upon the humidity of the environment around the flower; climate change may affect this environmental humidity, which in turn could have a negative effect on a visiting bee because the effectiveness of the humidity pattern will be altered.”

Paper:

‘Bumblebees can detect floral humidity’ in Journal of Experimental Biology by Michael J. M. Harrap, Natalie Hempel de Ibarra, Henry D. Knowles, Heather M. Whitney and Sean A. Rands

Issued by the University of Bristol Media & PR Team on Tuesday 22 June 2021.

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