Feeds:
Posts
Comments

Archive for the ‘Uncategorized’ Category

Sharing is Caring with Fire Ant Venom

USDA Agricultural Research Service sent this bulletin at 12/07/2022 09:15 AM EST

View as a webpageARS News ServiceARS News ServiceFire ants
ARS scientists are researching how fire ants use their venom to prevent diseases in their colonies. (Photo by Steve Ausmus)Sharing is Caring with Fire Ant VenomFor media inquiries contact: Jessica Ryan, (301) 892-0085
December 7, 2022Venom is associated with being harmful, but red imported fire ants are using their venom for its medicinal benefits by sharing the toxic substance with their nestmates, according to a study published in the Journal of Insect Physiology.Agricultural Research Service (ARS) scientists from the agency’s Biological Control of Pests Research Unit and Southern Insect Management Research Unit in Stoneville, Mississippi, discovered a new way that fire ants use their venom to prevent diseases in their colonies.”Venom works as a broad spectrum antibiotic and plays an important role in the fire ant social community by suppressing pathogen growth,” said Jian Chen, research entomologist at the Biological Control of Pests Research Unit.For fire ants, venom has different functions. Fire ants use venomous stings against intruders and immobilize their prey. Fire ants also take advantage of their venom’s antimicrobial properties in disease control by using it as an external surface disinfectant. Foraging ants come into contact with various pathogens in the environment. These pathogens threaten ants; especially when they share food with their nestmates.”One way to reduce exposure to infection through food is to distribute antibiotics into the digestive system of all individual ants,” said Chen. “Venom is an internal antibiotic in fire ants’ digestive systems.”To use venom as an internal antibiotic, fire ants share it by feeding the substance to their nestmates, including larvae and adults. In the study, researchers found nitrogenous organic compounds of venom, known as alkaloids, in crops and midguts of larvae. This finding indicates that trophallaxis, the transfer of food from mouth-to-mouth or mouth-to-anus feeding, must be involved in the transfer of venom since larvae do not produce alkaloids and depend on worker ants to be fed.According to Chen, larvae serve as a “communal stomach” for the colony and are the most vulnerable to infection. To keep colonies alive, fire ants must protect the larvae.Researchers also found that female alates (winged ants) shed their wings after a mating flight, burrow into the soil, and start new colonies. The new queen then provides venom alkaloids to her first batch of larvae in the colony. Then minim ant workers (the first batch of workers in a fire ant colony) emerge and then take over the role of providing venom to the larvae in the colony. The minim ant workers eventually die out, and the normal ant workers then become the colony’s venom donors. Thus, venom sharing occurs in every stage of colony development.As a social insect, in addition to individual immunity, fire ants have evolved social immunity based on the interaction among nestmates. This study indicates that venom sharing by feeding may be an essential component of fire and social immunity. This research will help scientists better understand the ways ants work together to avoid epidemics.The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.Interested in reading more about ARS research? Visit our news archiveU.S. DEPARTMENT OF AGRICULTURE
Agricultural Research Service

Read Full Post »

NEWSANIMALS

‘Murder hornets’ have a new common name: Northern giant hornet

Worries over rising anti-Asian bias added urgency to picking a new name for Asian giant hornets

portrait of a northern giant hornet specimen
U.S. insect scientists chose a new, mild common name — northern giant hornet — for what’s been sensationalized as a murder hornet. Until now, less sensational scientists called it the Asian giant hornet.HANNA ROYALS, MUSEUM COLLECTIONS: HYMENOPTERA, USDA APHIS PPQ, BUGWOOD.ORG (CC BY-NC 3.0)

Share this:

By Susan Milius

JULY 27, 2022 AT 5:38 PM

What’s been called a “murder hornet” or “Asian giant hornet” now has a somewhat official, maybe kinder, name. Meet the northern giant hornet.

That’s what the Entomological Society of America, or ESA, announced July 25 as the preferred plain-English common name for the big, orange-and-black Vespa mandarinia. The choice has at least as much to do with people as it does with hornets.

It’s a celebrity as insects go. By 2019, the species had hitchhiked across the Pacific and was already nesting in Canada probably also on the U.S. side of the border. News stories exclaimed over hornet queens as long as a human thumb and the hornets’ late summer raiding parties that mass-slaughter whole hives of adult honeybees to steal the chubby larvae as wasp food. V. mandarinia became the doomsday spirit insect for the start of COVID-19 times (SN: 5/29/20). As of late July, there have been no confirmed sightings this year of the hornet in Washington, the state at the center of the buzz in the United States, but trapping efforts are under way.

In that innocent earlier time, the ESA’s list of preferred common names didn’t have an entry for the species. “Murder hornet” was way too tabloid; the hornets don’t hunt people. Frontline scientists dealing with invaders in the Pacific Northwest took up the name “Asian giant hornet.”

Yet both “Asian” and “giant” troubled Chris Looney of the Washington State Department of Agriculture in Olympia. “Asian” is “at best neutral and uninformative,” he wrote when proposing an alternative name to ESA. All 22 species of Vespa hornets have some part of their range in Asia. So mentioning the continent does pretty much nothing to clarify which species is under discussion.

At worst, though, connecting Asia and a nervous-making insect feeds racist fears, Looney argued. He warned about a recent “rise in hate crimes and other odious behavior directed at people of Asian descent in countries across the globe.” He has heard multiple grumblings about the hornet as “another” unwelcome “thing from China,” he said. (The current invaders came from elsewhere in Asia.)

With such concerns in mind, ESA has launched the Better Common Names Project to fight racism embedded in names (SN: 8/25/21). In 2021, this effort led to retirement of a cringy old name for what’s now the spongy moth (SN: 3/10/22). Looney urged that a hornet common name avoid linking “Asian”with “a large insect that inspires fear and is under eradication.”

The trouble with just calling it “giant” is that other hornets also grow whoppingly big. One, Vespa soror, a mostly subtropical species, turned up as a large, one-hornet surprise in Vancouver in 2019. Those hornets grow about the same size as V. mandarinia and also will mass-slaughter honeybees.

The new name declaration finesses both size and geography. Based on rough distribution in their native Asian range, V. mandarinia is now the “northern giant hornet” and V. soror the “southern giant hornet.”

Read Full Post »

Perennial’ rice saves time and money, but comes with risks

PR23 variety doesn’t need to be replanted every year, but might create problems with pests, diseases, and weeds

Aerial view of villagers working in a field before transplanting rice seedlings in Huzhou, China
Farmers in China transplant seedlings for the seasonal rice harvest, which takes weeks of hard work for every hectare.WANG ZHENG/VCG VIA GETTY IMAGES

SHARE:

issue cover image

Table of contents

A version of this story appeared in Science, Vol 378, Issue 6620.Download PDF

Grains that grow year after year without having to be replanted could save money, help the environment, and reduce the need for back-breaking labor. Now, the largest real-world test of such a crop—a perennial rice grown in China—is showing promise. Perennial rice can yield harvests as plentiful as the conventional, annually planted crop while benefiting the soil and saving smallholder farmers considerable labor and expense, researchers have found.

“This is the first robust case study” of perennial rice, says Sieglinde Snapp, a soil and crop scientist at the International Maize and Wheat Improvement Center who was not involved with the work.

The results show the crop is “a potential game changer,” adds Clemens Grünbühel, an ecological anthropologist at the Australian Centre for International Agricultural Research who studies agriculture and rural development. The advance could reduce labor or allow China to grow more food, he and others say.

But whether the perennial rice will catch on is hard to predict, says Susan McCouch, a rice geneticist at Cornell University, because seasonal replanting still has some advantages over the new crop.

All rice is perennial to some extent. Unlike wheat or corn, rice roots sprout new stems after harvest. The trouble is that this second growth doesn’t yield much grain, which is why farmers plow up the paddies and plant new seedlings. The improved perennial rice, in contrast, grows back vigorously for a second harvest. Researchers developed it by crossing an Asian variety of rice with a wild, perennial relative from Nigeria. Improving the offspring took decades, and in 2018 a variety called Perennial Rice 23 (PR23) became commercially available to Chinese farmers. This was a “scientific breakthrough,” says Koichi Futakuchi, a crop scientist at the Africa Rice Center.

But how many times PR23 could be harvested before its yield dropped was unclear, as was the magnitude of any economic and environmental benefits. So Fengyi Hu, a geneticist and agronomist at Yunnan University, and others organized longer experiments. They arranged with farmers in three locations to plant the rice and harvest it twice a year for 5 years, while also growing typical rice varieties that were replanted each season.

Over 4 years PR23 averaged 6.8 tons of rice per hectare, slightly higher than the annual rice, they report today in Nature Sustainability. As hoped, the perennial crop tended to grow back again and again without sacrificing the size of the harvest. In the fifth year, however, the yields of PR23 declined for some reason, suggesting it needed to be replanted.

The perennial rice also improved the soil. Compared with annual rice, the crop left more nutrients—organic carbon and total nitrogen—in the soil, which also held water better. Retaining water doesn’t matter for irrigated rice, but it would benefit rice grown in regions that depend on rainfall. By next year, Hu says, the researchers hope to have results from a 6-year trial of another important factor: how much greenhouse gas perennial rice emits. Existing paddy-grown rice is a major global source of methane, for example, which contributes to global warming.

But is the new rice good for farmers? To find out, the researchers compared the effort involved in cultivating PR23 and the annual varieties. Fuel for plowing, the seedlings themselves, and other costs were basically the same the first year, typically $2600 per hectare. But for each following year the perennial rice cost half as much to manage. Each hectare also took between 68 and 77 fewer days of labor.

Those advantages are luring farmers. In southern China, Yunnan University provided seed and training to outreach workers, and the total area planted in 2020 quadrupled to 15,333 hectares last year. (That’s still a tiny fraction of China’s 27 million hectares of rice fields.) The government has also helped promote perennial rice, Hu says. This year, PR23 is on a list of 29 varieties recommended to farmers by China’s Ministry of Agriculture and Rural Affairs.

The largest beneficiary of the labor savings will likely be women and children, who do most of the transplanting of rice seedlings in many rice-growing countries, says Len Wade, an agricultural ecologist at the University of Queensland, St. Lucia, who helped test the rice variety. Mothers will have more time to “look after the family and get the children to school with breakfast and not exhausted,” he says. Farmers could also plant abandoned fields and grow more rice, or they might earn more income in side jobs like construction.

Still, Grünbühel cautions, more study of the impact on households will be needed to see how popular PR23 is likely to be and how the labor savings might affect farmers’ lives.

Researchers note potential risks. Because PR23 enables farmers to till less, fungi and other pathogens can build up in the fields. Insects can persist in the stubble after harvest, because it’s not plowed under, then transmit viruses when they feed on the regenerating sprouts in the spring. And without tilling, weeds can flourish; the researchers found that fields with PR23 needed one to two more herbicide treatments than regular rice. They also note that it’s more work to resow the perennial rice when its yield falters, because its larger and deeper roots need to be killed.

The potential benefits—and any downsides—will soon come into sharper focus. The perennial rice is being tried in 17 countries in Asia and Africa. Another major target is uplands in Asia, where plowing for conventional rise hastens soil erosion in small, terraced rice fields.

The creators of PR23 “have a proof of concept,” Snapp says. “I hope that there’s some momentum building.”


doi: 10.1126/science.adf6990

RELEVANT TAGS:

ASIA/PACIFICPLANTS & ANIMALS

ABOUT THE AUTHOR

Erik Stokstad

mailTwitter

Author

Erik Stokstad is a reporter at Science, covering environmental issues. 


Read Full Post »

Husker study: Brazil can grow more soybeans without deforesting Amazon | IANR News (unl.edu)

Read Full Post »

Tuesday, 04 October 2022 12:01:49

PestNet

Grahame Jackson posted a new submission ‘Researchers propose ectomycorrhizal fungi’s role to be integrated into carbon accounting’

Submission

Researchers propose ectomycorrhizal fungi’s role to be integrated into carbon accounting

Mirage
https://www.miragenews.com/researchers-propose-ectomycorrhizal-fungis-role-866860/

Researchers from the University of Helsinki, Natural Resources Institute Finland and Swedish University of Agricultural Sciences propose that the role of the ectomycorrhizal fungi should be taken into account in models of carbon accounting.

A new study led by the University of Helsinki provides evidence that the observed decline of carbon use efficiency and net ecosystem exchange from south to north in the boreal forest may be caused by the abundance of ectomycorrhizal fungi.

The proposed approach could easily be included in carbon balance models for quantifying ectomycorrhizal fungi carbon use without having to engage in more complex analysis of carbon and nutrient interactions underlying ectomycorrhizal fungi processes.

“The results of the study underline the need for a better understanding of the role of micro-organisms as users of carbon but also as a machinery generating carbon residues that may have longer lifespans,” says the first author of the study Annikki Mäkelä from the Faculty of Agriculture and Forestry, University of Helsinki.

The study suggests that this approach can improve prediction of biomass growth across different soils with different microbial composition.

Read Full Post »

Wednesday, 21 September 2022 00:51:45

Grahame Jackson posted a new submission ‘Decoding how bacteria talk with each other’

Submission

Decoding how bacteria talk with each other

University of Wisconsin Maddison
https://news.wisc.edu/decoding-how-bacteria-talk-with-each-other

Bacteria, the smallest living organisms in the world, form communities where unified bodies of individuals live together, contribute a share of the property and share common interests.

The soil around a plant’s roots contains millions of organisms interacting constantly — too many busy players to study at once, despite the importance of understanding how microbes mingle.

In a study published in the journal mBio, researchers at the University of Wisconsin–Madison learned that a drastically scaled-down model of a microbial community makes it possible to observe some of the complex interactions. In doing so, they discovered a key player in microbial communication: the presence or absence of an antibiotic compound produced by one of the community members affected the behavior of the other two members.

Little is understood about how individual microbes interact with each other in communities, but that knowledge holds incredible promise.

For example, the bacteria Bacillus cereus can protect plants by producing an antibiotic that deters the pathogen that causes “damping off,” a disease that kills seedlings and is costly to farmers. But biocontrol agents like B. cereus are not always effective. Sometimes plants treated with B. cereus flourish, sometimes they don’t — and researchers are trying to understand why.

Amanda Hurley

“Bacteria do not live in isolation,” says Amanda Hurley, lead author of the new study; AAAS Science and Technology Policy Fellow; and former postdoc in the lab of UW–Madison professor Jo Handelsman, director of the Wisconsin Institute for Discovery.

“If we could figure out how interactions between species change in the presence of multiple species, we can start to understand communication trends of whole microbial communities Using chemistry or genetics, we could interrupt certain conversations and amplify others, leading to microbiomes that interact with their environments more positively and predictably, whether it be humans, crops or the soil itself.”

Deciphering the interactions between microorganisms could help in engineering an environment more favorable to Bacillus cereus. Hurley and co-authors Marc Chevrette, former postdoc in the Handelsman lab and currently assistant professor at the University of Florida, and Natalia Rosario-Melendez, graduate student in the Handelsman lab, set out to decode and translate the chemical conversations. The group created a model system composed of three species — Flavobacterium johnsoniae and Pseudomonas koreensis were isolated with B. cereus from field-grown soybean roots — which they dubbed “The Hitchhikers of the Rhizosphere” or THOR.

Marc Chevrette

Bacteria often communicate through the language of chemistry. Manipulating that chemistry using genes and chemicals could change the conversation and make Bacillus cereus feel welcome on plant roots.

The researchers built profiles of the THOR organisms using their mRNA, molecules produced when a gene is expressed. In each combination of THOR bacteria, the researchers looked for differences in gene expression. The THOR organisms responded to each other differently in every combination, and when all three species were together, new things started to happen that did not happen in any of the pairs or single conditions.

In the THOR community, gene expression was dominated by interactions with one member, P. koreensis. The results were mediated by the presence of the antibiotic koreenceine — the metaphorical hammer of THOR. This single molecule appears to affect the expression and interaction of thousands of genes across community networks. Determining how koreenceine regulates the community’s genes will be a fruitful avenue for further investigation, according to the researchers.

The study validates Handelsman’s early idea that communities are worth investigating, because the activity within the community is not just the sum of the members but reflects community properties.

“Traditionally, people only look at a single organism. What makes our study different is that we looked at the community,” says Chevrette. “Communities are different. There is something inherently unique to a community that makes it different than the sum of its parts. Utilizing the simplicity of model microbiomes may help us with the challenge of understanding microbes in complex communities, and how they can be altered to improve human, environmental, and agricultural health.”

This research was supported by grants from the Department of Defense (W911NF1910269) and Department of Agriculture (2019-2018-08058 and 2020-67012-31772).


Read Full Post »

Scientists recreate the song of a cricket-like insect that hasn’t been seen in 150 years

It’s supposed to sound like its ancestors from the Jurassic.

Tibi Puiu by Tibi Puiu

 August 15, 2022

in AnimalsBiologyNews

Reading Time: 4 mins read

A A

Share on FacebookShare on TwitterSubmit to Reddit

The katydid Prophalangopsis obscura has been lost since it was first found. Credit:  Charlie Woodrow.

Although tiny, some of the noisiest inhabitants of Earth are, in fact, insects. Whether it’s the hum of a bee, the buzz of a fly, or the chirping of a cricket, there’s really no escaping their constant, noisy chatter. Humans are so used to these sounds that most of the time we just ignore them, but here’s an interesting thought: did they always sound like this?

Insects first appeared around the same time as the earliest land plants around 480 million years ago. In no time, they came to dominate the planet. Even today, it is estimated that around 75% of the over 8 million different species of life on Earth are insects, most of which remain to be discovered.

Some of the noisiest insects are thought to belong to an ancient family called Prophalangopsidae, which scientists know about from fossils from the Jurassic period. They’re related to modern crickets and katydids, but there are only eight modern descendants that we know of.

One of them is Prophalangopsis obscura, an insect first described in 1869 by British naturalist Francis Walker. That was also the last time anyone has seen it, despite biologists’ best efforts to track it down. Many still have hope they’ll find one in India, its supposed habitat.

The Natural History Museum’s specimen of P. obscura is the only confirmed member of its species. Credit:  The Trustees of the Natural History Museum, London.

For more than 150 years, this lonely specimen has been sitting in the collection of the Natural History Museum in London. Now, scientists have made P. obscura sing again, digitally recreating its long-lost call in the hopes that it could be used to finally locate the insect in the wild.

“While we’re only dealing with one specimen, it’s one of just a handful of species which survives from a group of grasshopper and cricket relatives that likely dominated during the Jurassic,” said co-author Ed Baker, a bioacoustics researcher at the Natural History Museum in London.

Like crickets, locusts, and grasshoppers, P. obscura more than likely produces songs using a process known as stridulation, or the rubbing together of body parts such as the wings and legs to make sounds. The researchers generated 3D models of each of the lonely insect’s wings and determined their resonant frequency, which they used to recreate the tune of its song based on a library of insect recordings from hundreds of species.

Read Full Post »

Eye Doctor’s Tool Offers New Look at Marvel of Moth Eyes

ENTOMOLOGY TODAY  2 COMMENTS

A tool commonly used in ophthalmology finds a new use in entomology: Observing how a moth’s eye adjusts to see in both light and dark environments. Moths such as the winter cutworm (Noctua pronuba, also known as the large yellow underwing), use a light-absorbing pigment that moves position to limit the light within the eye. The process takes approximately 30 minutes and only occurs in live specimens, making it difficult to observe. A new technique using optical coherence tomography, however, opens new doors for studying this process. (Image by Sam R via iNaturalistCC BY-NC 4.0)

By Ed Ricciuti

If you are into puns, you might call it an eye-opening innovation.

An optometrist in the United Kingdom has adapted technology for diagnosing human eye disease to instead scan how the eye of a living nocturnal moth regulates light input. To date, this light-regulation process has been visualized only in still images from dead specimens, but the new technique records in real time the moth eye adapting to changing light as it unfolds, dynamically.

An article by optometrist Simon Berry, MCOptom, published in June in the journal Environmental Entomology, describes the first use of optical coherence tomography (OCT) to view anatomical detail in the compound eye, common to insects, crustaceans, and other arthropods. Like medical ultrasound, OCT technology images biological tissue but does so by using light instead of sound. It is widely used in ophthalmology to obtain cross-sectional information about structures within the eye, making it an important diagnostic tool in the evaluation of human eye diseases. You may have peered into one if you have been examined for macular disease or if you are elderly; it is used routinely in many patients over 70.

Adapting to seeing in the dark is one of the evolutionary problems that nocturnal animals have had to overcome. Conversely, they can be challenged by the bright light of day. “During the night the light levels are low, so their eyes need to be very sensitive; but, they also need a way of adapting to environmental light conditions, and protecting those sensitive organs, if a bright light is encountered,” says Berry. “Human eyes have a pupil that changes size to regulate light input to the eye. Moths use a light-absorbing pigment that moves position to limit the light within the eye.”

In the moth’s eye, photopigment granules are stored between crystalline cone-shaped structures, or Semper cells, beneath the cornea. Behind that layer, the compound eye of nocturnal insects—defined as a “superposition” eye—has a transparent region called the clear zone. To decrease the brightness of light, the dark pigment is extruded from the cones into the clear zone. Like clouds blocking the sun, the pigment restricts the amount of light reaching the rhabdoms, photoreceptive structures in a layer at the back of the eye. In darkness, the pigment migrates away from the zone back into the cone layer. In effect, the concentration of pigment granules lessens to permit more light and increases to reduce it. (Image by Juliet Percival, originally published in Berry 2022, Environmental Entomology)

In the moth’s eye, photopigment granules are stored between crystalline cone-shaped structures, or Semper cells, beneath the cornea. Behind that layer, the compound eye of nocturnal insects—defined as a “superposition” eye—has a transparent region called the clear zone. To decrease the brightness of light, the dark pigment is extruded from the cones into the clear zone. Like clouds blocking the sun, the pigment restricts the amount of light reaching the rhabdoms, photoreceptive structures in a layer at the back of the eye. In darkness, the pigment migrates away from the zone back into the cone layer. In effect, the concentration of pigment granules lessens to permit more light and increases to reduce it.

The migration of pigment is difficult to record because it is a dynamic process, Berry says, and takes place only when a moth is alive. “By necessity, any microscopic examination of the eye requires dissection of a dead insect and will show a snap-shot of the adaptive state at that point in time,” Berry writes his paper. Thus, the fact that OCT is non-invasive is critical to the new method for observing this process.

Moths used in the study were trapped, scanned, and later released. During the experiment, the moths were adapted to darkness in a dark bag for at least an hour. The first scan was completed with the room in darkness to try and ensure the insect stayed dark adapted. A white LED light source was then turned, on and various scans were taken as the insect became light adapted.

Optical coherence tomography is well suited to observing the physiological adaptation process to light in moth eyes because the process is relatively slow, taking approximately 30 minutes to transition between fully dark-adapted to fully light-adapted. (Image originally published in Berry 2022, Environmental Entomology)

Berry found that when a moth is in a dark-adapted state, the clear zone is optically transparent, and light emitted by the OCT passes through it to the rhabdom layer, which serves like the retina of the human eye, resolving wavelengths of light so it can be processed to images by the brain. In a light-adapted state, pigment that has migrated into the clear zone changes its composition so it filters out light.

OCT is well suited to observing the physiological adaptation process to light because the process is relatively slow—circa 30 minutes—says Berry, and during this period the insect’s perception is not optimized for the environmental light levels. For example, if a light source causes an insect to light adapt and then that light source is taken away, it will take a period of time for it to become dark adapted and see effectively in low light levels.

Video Player

00:00

00:00

1. Optical coherence tomography scan: Noctua pronuba, “yellow underwing” moth eye

2. Optical coherence tomography scan: Plusia festucae, “gold spot” moth eye

Optometrist Simon Berry, MCOptom, reports in the journal Environmental Entomology on the use of optical coherence tomography for imaging the eye of a live moth as it adapts for vision in light or dark environments. In two videos here, images from the scans are sequenced to show the process over time. (Videos by Simon Berry, MCOptom)

From the OCT scans, it appears that the beginning of the pigment migration is not instantaneous but rather the pigment migration becomes visible after a short delay. “This may be because it takes time for the pigment to migrate and show in the scan,” says Berry. However, there could possibly be a biological reason why this may occur. The lag before pigment migration means that if the insect encounters a brief flash of bright light, it may be able to recover quickly because the pigment migration has not started. It may not lose its fully dark-adapted state immediately, as humans do, and so its vision not impeded. Conversely, the time lag in transition from light to dark adaption may disadvantage moths with light-adapted eyes for a time period if they move away from a light source into the dark.

“Further research is needed to determine whether the state of light adaption affects moth behavior,” says Berry. “I really do think that OCT can be a useful tool in entomology and could possibly help explain some of moth behaviour around light sources. It opens up another way of examining the compound eye, and because it is non-invasive it can be used to look at dynamic processes like light adaption in ways not previously possible.”

Read More

The Use of Optical Coherence Tomography to Demonstrate Dark and Light Adaptation in a Live Moth

Environmental Entomology

Read Full Post »

Eastern Daily Press > News

Farm fields dyed with bright colours to confuse crop pests

Author Picture Icon

Chris Hill

0Published: 10:12 AM July 1, 2022

Soil is being dyed in different colours to confuse disease-carrying aphids in this BBRO ‘camo cropping’ trial at Morley Farms – Credit: BBRO

Scientists are spraying coloured dyes onto farm fields to confuse crop pests as part of their efforts to find natural alternatives to chemical pesticides.

The “camo-cropping” trial by the Norwich-based British Beet Research Organisation (BBRO) was one of the many industry innovations on display at the Royal Norfolk Show.

Soil is being dyed in different colours to conceal the emerging crop from disease-carrying aphids, which have become an increasing problem in the absence of banned pesticides. 

Ches Broom of the British Beet Research Organisation illustrating “camo cropping” soil dye trials at the Royal Norfolk Show – Credit: Chris Hill

The trial at Morley Farms, near Wymondham, is part of the BBRO’s search for “nature-based solutions” to protect the region’s sugar beet crops.

They include trying to attract beneficial insects and natural insect predators into the crop by planting alternative host plants, such as the aphids’ preferred brassicas, alongside the sugar beet.

Ches Broom, knowledge exchange manager for BBRO, said the “camo-cropping” idea came from a farmer who had used under-sown barley in a sugar beet crop in an effort to stop wind-blow problems – and found they had also reduced pest and virus levels.

“We know it works, but we did have a problem in trying to destroy the barley without knocking back the sugar beet,” she said.

“So we are using food-based dyes instead. We spray the soil, and the aphids flying over don’t see the beet coming through so they are flying past.

“If we have flowering plants or a brassica strip around the field, the idea is that they will miss the sugar beet and go there instead.

“We are trying some weird and wacky things, but it might be the thing that we need.

“As an industry we don’t want to be using too many chemicals. We want natural solutions.”

Beneficial insects such as ladybirds are being encouraged into sugar beet crops as natural predators to control disease-carrying aphids – Credit: Chris HIll

Other innovations at the show ranged from hi-tech commercial machinery created by well-funded research and development teams, to home-made prototype inventions forged in farm workshops.

Dr Belinda Clarke, director of Agri-TechE, which hosts the show’s innovation hub, said: “I think what is really exciting is that innovation can operate at a number of levels.

“It can be the highly-complex, expensive R&D that needs very sophisticated equipment and PhD-level skills, or it can be innovation at farm level – even a change to a business model, or something as simple as spraying a different colour on the land to confuse the senses of insects.”

Read Full Post »

Unraveling sex determination in Bursaphelenchus nematodes: A path towards pest control

by Meiji University

Unraveling sex determination in Bursaphelenchus nematodes: A path towards pest control
Scientists discover that sex determination in nematodes of the genus Bursaphelenchus can be attributed to random events rather than well-known mechanisms such as genetic or environmental sex determination. Credit: Associate Professor Ryoji Shinya, Meiji University

The sex and sexual characteristics constitute key aspects of an organism’s life and are determined by a biological process known as sex determination. These ever-evolving mechanisms are broadly classified based on the type of “switch” that triggers them. Genetic sex determination is dependent on sex chromosomes, such as the X and Y chromosomes in human beings, whereas environmental sex determination depends on factors like temperature and the local ratio between males and females. Although most sex determination mechanisms are genetic or environmental, a third type of sex determination, which depends on completely random factors, also exists. This, however, has not been explored completely.

https://b061635754117d291d1441647ea7032d.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

The sex determination mechanism of Caenorhabditis elegans, a species of nematode, or our common garden-variety roundworm, is one of the best understood aspects of its biology. In its case, embryos with two X chromosomes, or the XX embryos, develop into hermaphrodites, while the XO embryos, which have one sex chromosome—the X chromosome—develop into males. Several species of nematodes have a sex determination mechanism similar to that of C. elegans. Interestingly, however, some nematode species also rely on the XX/XY system for sex determination, with both X and Y types of sex chromosomes, as well on environmental factors. Unfortunately, the mechanisms that cause this variance in sex-determination between nematode species have remained a mystery thus far.

Recently, a group of researchers led by Associate Professor Ryoji Shinya from Meiji University, Japan, Professor Paul Sternberg from the California Institute of Technology, U.S., and Associate Professor Taisei Kikuchi from the University of Miyazaki, Japan, conducted a study to understand sex determination in two nematode species—Bursaphelenchus xylophilus and Bursaphelenchus okinawaensis. Dr. Shinya’s team have long been engaged with nematode research. In this new study, they conducted a sex-specific genome-wide comparative analysis to determine the initial trigger of sex determination in the two Bursaphelenchus species, and genetic screening to determine the genetic cascade that followed the trigger.

In their study published in Nature Communications, the researchers report that there is no difference in the number of chromosomes, or the genome, between males and females in B. xylophilus and between males and hermaphrodites in B. okinawaensis. This suggests that these sexes in both nematode species have identical genomes and no sex chromosomes. Thus, sex determination in these species must be through non-genetic mechanisms.Play

00:00

03:06MuteSettingsPIPEnter fullscreen

PlayCredit: Meiji University, Tokyo, Japan

To explore this further, the team conducted an analysis to find out if environmental factors such as temperature, nutrient availability, and population density influenced sex determination in these organisms. They observed that these factors had a minimal effect on sex determination in the larvae of these species, and that none of the larvae turned into males.

Considering that the offspring produced through self-fertilization in B. okinawaensis are essentially isogenic clones, it is clear that genetic differences are not required for sex determination in B. okinawaensis. In addition, even under fixed environmental conditions, genetically identical individuals of B. okinawaensis differentiate into hermaphrodites and males. The team suggests that the sex of B. okinawaensis nematodes is mainly determined by stochastic expression of an unknown trigger gene and/or developmental noise. In other words, sex differentiation occurs as a result of random events during development.

The team also compared the orthologs, i.e., genes related by common descent, of similar sequences in C. elegans, B. xylophilus, and B. okinawaensis. They found that only downstream genes in these three nematodes were conserved, indicating that the Bursaphelenchus genus has a different sex determination trigger than does C. elegans. In addition, they conducted genetic analyses and identified one major sex determining locus in B. okinawaensis, known as Bok-tra-1a. Using bioinformatics and RNA-sequencing, they observed a conservation of putative targets in this regulating gene, further supporting the findings that indicated the conservation of downstream functions. This implies that nematode sex differentiation might have evolved from this downstream regulator.

“Our discovery of a striking new mode of sex determination in the nematode phylum might help not only with lab studies of parasitic nematodes, but also contribute to population engineering,” observed an excited Dr. Shinya.

Indicating the importance of these findings in pest control, Dr. Shinya says, “Damage caused by plant-parasitic nematodes is estimated at 80 billion USD per year. Conventional nematicides are harmful for the environment. Understanding the sex determination mechanisms of plant parasitic nematodes can help in developing sterile strains that are not parasitic but may help reduce nematode populations in a safe and sustainable way.”


Explore further

Parasitic worms reveal new insights into the evolution of sex and sex chromosomes


More information: Ryoji Shinya et al, Possible stochastic sex determination in Bursaphelenchus nematodes, Nature Communications (2022). DOI: 10.1038/s41467-022-30173-2

Journal information: Nature Communications 

Provided by Meiji University

Read Full Post »

Francis to retire after 45 years at Nebraska Charles “Chuck” Francis, University of Nebraska–Lincoln professor in agronomy and horticulture, will retire June 30 after a 45-year career at Nebraska.

GPPN Followers:

I have attached the article on Chuck Francis because he has had an extensive international career and I am sure that some of you readers of the GPPN have had him visit your country, he may have been your mentor at the University of Nebraska or you have met him somewhere..

E.A. “Short” Heinrichs

IAPPS Secretary General and Membership Manager

eheinrichs2@unl.edu

Francis to retire after 45 years at Nebraska Charles “Chuck” Francis, University of Nebraska–Lincoln professor in agronomy and horticulture, will retire June 30 after a 45-year career at Nebraska. Charles “Chuck” Francis

Read Full Post »

Older Posts »