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cambodia seederModifies Machinery, Improves Quality of Rice

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This post is written by Sara Hendery, Communications Coordinator for the Feed the Future Innovation Lab for Integrated Pest Management. 

Outside his home in Battambang, Cambodia, In Soun leans against a thin metal wheel almost as tall as he is. One after another, he gathers parts and pieces in a myriad of shapes—curled-up connectors, big and small containers, cylindrical plastic tubes. Many of them are attachments Soun has commissioned local manufacturers to make for the Eli Rice Seeder he leans against, a machine that plants rice in uniform rows instead of the traditional, labor-intensive method of manual transplanting or broadcasting by hand.

Soun is the first farmer in his village to use a mechanized tractor — now, he can add innovator to his list of titles as well.

Soun learned about Agri-Smart, the Eli Seeder developer, at a trade fair organized by the International Rice Research Institute (IRRI) and Feed the Future Innovation Lab for Integrated Pest Management (IPM IL). The quarterly event aims to increase access to productive resources by introducing farmers to private sector companies selling integrated pest management (IPM) tools and offering discounts for on-site purchases.

Utilizing air pressure, the Eli Seeder shoots seeds into the ground in straight rows that are not overconcentrated and easy to weed between. The process reduces seed rates, fertilizer use, pesticide use, and labor time. A low seed rate encourages farmers to buy more expensive, but better quality seeds, which garner higher prices at the market.

After using the seeder in his fields, Soun began thinking of other ways it could contribute to rice production. He added modifications such as new wheels, more productive seed vessels, and a sprayer for diffusing Trichoderma, an IPM IL-promoted biopesticide that boosts plant defense mechanisms against pests and disease. His Trichoderma modification alone has reduced his fungicide spraying rate to zero. Spraying it by hand used to take Soun 2 hours per hectare, but his modified sprayer requires just 20 minutes.

“My neighbors used to say ‘don’t bring the tractor through my field’,” Soun said, “but now they want to follow what I’m doing.”

Soun earns an additional $37 per hectare for using the Eli Rice Seeder in his neighbors’ fields, who are following his low seed rate.

Using the Eli Seeder has reduced Soun’s seed rate from 300kg per hectare to 80kg per hectare and has significantly decreased fertilizer rates. Excess fertilizer can make plants more susceptible to pests and disease—if Soun increased his seed rate by just 10kg, he’d have to add an entire bag of fertilizer to his inputs, which would be costly.

In Cambodia, and many developing countries, poor seed quality is a major contributing factor to food insecurity. Farmers use recycled seeds from previous seasons, which means planting excessive amounts and planting old weed seeds as well, which farmers combat with pesticides. In addition to pests and disease, exposed rice seeds also face the threat of being eaten by rats and birds or whisked away by drought and flooding.

“The quality of the grain is now better,” Soun said. “When a trader comes to buy it, they have no complaints or questions.

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‘Kurikong’ disease threatens Philippine mango export

Philippine government researchers are in the thick of finalizing their studies on how to address the problem caused by the Cecid fly, as the infestation threatens the nation’s mango yield.

Secretary William Dar has ordered Undersecretary Evelyn Lavina of the high-value crops program to aid in research and development initiatives which could address the Cecid fly or locally called “kurikong” infestation.

The Cecid fly is a mosquito-like insect that lays its eggs on the fruit surface and young mango leaves, where its larvae bore into the fruit and feed on it. Such infestation is threatening Philippine mango production, which was recorded at 737,928 tons in 2019.

Data from the Philippine Statistics Authority (PSA) show that exports of fresh and dried mangoes amounted to $17.88 million last year, 4% higher than in 2018.

Source: gmanetwork.com

 

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tuta larva on tomato (2)

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Tuta absoluta pest continues to hit Majorca

The Tuta absoluta pest is wreaking havoc again in Majorca, especially in the Sineu road area. The Tuta has been present on the island since 2008, but its impact has worsened since last summer mainly due to two factors: its resistance to pesticides and climate change, which has brought mild temperatures in winter that do not kill the moth.

Jaume Pocoví, from Unió de Pagesos, says that many of the tomato plantations in greenhouses have been lost and that the situation could get worse ahead of summer. “The situation is especially worrying in greenhouse plantations, where the production cycle is not broken, since the insect has great reproductive potential,” he says.

One of the recommendations made by the Unió de Pagesos and the General Directorate of Agriculture is that, once the production cycle is over, the producers should uproot the tomato plants and not wait for them to dry before eliminating the plants. “Once the production cycle is over, the plants should be burned or buried to prevent the proliferation of the moth,” says Andreu Joan, head of the Council’s Department of Agriculture.

Last December, Joan participated in an international meeting where various strategies against tomato pests and diseases were analyzed, since the Tuta affects a good part of the Mediterranean area and has become one of the main threats for this type of crop.

Tomatoes are one of the most important horticultural crops in the Balearic Islands, with ​​366 hectares and a production volume totalling over 8,700 tons, according to the Government.

 

Source: ultimahora.es

 

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El Salvador declares a phytosanitary emergency due to HLB

The Ministry of Agriculture and Livestock (MAG) of El Salvador has declared a phytosanitary emergency due to the Huanglongbing (HLB) pest that is affecting the country’s citrus.

The institution has initiated a control and eradication plan for this pest, which consists of taking samples across the country to learn about the situation of citrus plantations and verify the extent to which the productions are affected. In addition, a telephone number will be enabled so that producers can request inspections and technical support.

The plan also involves managing the purchase of reagents to conduct tests and diagnoses, strengthening the laboratory network and prohibiting the sale of uncertified plants, according to a MAG press release.

The presidential commissioner of Operations and Government Cabinet, Carolina Recinos, said that this disease was detected in previous years, but past administrations hid the problem. She said that the current Government will file a complaint with the Attorney General’s Office (FGR) to investigate the case. The head of the MAG, Pablo Anliker, said that the pest was first detected in 2013.

The MAG also said that the pest only affects plantations and does not put human or animal health at risk. The fruit also represents no risk of contagion.

The disease has already been officially detected in countries of the region such as Guatemala (2009), Honduras (2010), Nicaragua (2010), Costa Rica (2011) and Belize (2009).

Source: elmundo.sv

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Researchers apply new technology to identify plant pathogen strains in Virginia

By Kendall Daniels

virginia tech logoWhen emerging plant pathogens go undetected, they have the potential to negatively affect food industries, conservation efforts, and even human health. And, just like emerging human pathogens, such as the 2019 novel Coronavirus, emerging plant pathogens need to be diagnosed as soon as possible to prevent them from spreading.

Genetic sequencing technologies are powerful tools that are used for the early detection and precise identification of pathogens; they have shown great improvement over the past 20 years. Using these novel technologies, scientists can identify pathogens down to their distinct DNA sequences, without the time- and labor-intensive need to grow pathogens in the lab.

Scientists at Virginia Tech are taking advantage of this technological revolution by developing a way to apply these technologies to identifying diseases in crops.

“We truly try to take advantage of the DNA sequencing revolution. However, it’s not enough to just sequence DNA. What we focus on in the lab is to combine the power of DNA sequencing with the power of new computer algorithms to interpret the DNA sequences to precisely and quickly identify these pathogens,” said Boris Vinatzer, professor in the School of Plant and Environmental Sciences in the College of Agriculture and Life Sciences and an affiliated faculty member of the Fralin Life Sciences Institute.

Vinatzer recently published his findings in the journal Phytopathology, along with his graduate students and collaborators Song Li, an assistant professor in the School of Plant and Environmental Sciences, and Lenwood Heath, a professor of the Department of Computer Science in the College of Engineering.

For this study, Vinatzer’s team wanted to determine if an Oxford Nanopore Sequencing MinION device and a combination of different bioinformatic programs and sequence databases would be successful in identifying bacterial pathogens down to the exact outbreak strain.

When tested on tomato plants grown on the Eastern Shore of Virginia, the MinION device recognized Xanthomonas perforans, a proteobacteria responsible for bacterial leaf spot in tomato plants, as the pathogen in question.

What was even more impressive is the fact that the team was able to make their identifications down to the strain level. Strain identification poses a serious challenge to scientists because strains can be difficult to distinguish from one another. Without the proper technology and databases, new strains could be misidentified and the diseases they cause go untreated.

“If you want to know if it’s a new strain that is causing a disease outbreak, you need to fine-tune your method. We have successfully done that. In fact, we didn’t just find out that the pathogen that causes the disease in Virginia tomatoes belongs to the species X. perforans, we also identified which group of strains within the species it belongs to. Luckily, in this case, we found that the pathogen belongs to a group of strains that is common in Florida that has been circulating in the U.S. for years. Therefore, eradication will not be necessary,” said Vinatzer.

In the past, scientists would have to run a separate test for every possible pathogen that could be in a sample. With new sequencing technologies, just one test can be used to identify anything and everything that is in a plant sample – including bacteria, fungi, and viruses.

After the DNA sequences are obtained, scientists must then feed sequence data into a database to compare them with reference sequences, which will tell them exactly what pathogen they are facing. Since databases can be accessed worldwide, local scientists can easily identify emerging pathogens by using data from where the pathogen has already been established.

However, at the time of the study, a comprehensive database that could precisely identify plant pathogens did not exist. Therefore, Vinatzer and Heath decided to take matters into their own hands and create their own database, LINbase. This database is unique in its use of Life Identification Numbers (LINs), which are like GPS coordinates. Each bacterial isolate has a number that scientists can reference and then use to classify and identify bacterial genome sequences to the strain level.

The lab’s ultimate goal is to improve and then transfer their new sequencing technology and computer algorithms to the Plant Disease Clinic at Virginia Tech, which provides plant disease diagnostic services to farmers, nurseries, and homeowners as part of Virginia Cooperative Extension. Eventually, the lab hopes to extend its reach to other plant disease clinics from around the world.

The technology could eventually be deployed in the field, along with automated sampling devices from the SmartFarm Innovation Network, an initiative of Virginia Tech’s College of Agriculture and Life Sciences, to develop and deploy innovative technologies in food, agricultural, and natural resources production systems in Virginia.

“The Oxford Nanopore Sequencing MinION device is one of those technologies that will really have an impact and I think it will save growers a lot of money. By being fast and more precise in identifying diseases, growers can intervene early and manage diseases effectively, thus reducing losses in crop yield and quality,” said Vinatzer.

With the success of their recent study, the lab’s next steps involve further reducing the amount of time that it takes for pathogen identification. The goal is to decrease the time that it takes from receiving a plant sample to identifying the pathogen strain from days to hours.

Vinatzer, Heath, and Li, would like to acknowledge seed funding from the cyberbiosecurity initiative, led by the College of Agriculture and Life Sciences. The Vinatzer lab also uses the MinION sequencer as part of a larger NSF-funded project that focuses on bacteria in precipitation.


Insects’ ability to smell is phenomenally diverse, a new protein structure hints at how

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A view of the Orco channel from above, looking down into the pore. When odorant receptor sequences were mapped onto this Orco channel structure, some areas were highly similar, shown in magenta, and other areas were variable, shown in cyan. Most similarities in odorant receptors are concentrated along the central pore, leaving the rest of the protein free to diversify, suggesting how the architecture of this receptor family accommodates its remarkable sequence diversity and facilitates the evolution of odor tuning. Credit: Vanessa Ruta.

Even though they don’t have conventional noses, insects have adapted to smell odors in nearly every imaginable niche. Mosquitoes find us by our odor molecules binding to odor receptors on their antennae, bees are drawn to flowers the same way, whereas ticks detect an approaching host using receptors on their forelegs. Insects’ ability to smell is uniquely adapted to their needs and habitats and Vanessa Ruta, Associate Professor at Rockefeller University, reveals a key to this versatility in research presented on Monday, February 17 at the 64th Annual Meeting of the Biophysical Society in San Diego, California.

“All animals use large families of olfactory receptors to detect the incredible variety of chemicals that exist around us. Insects evolved a unique molecular solution, the largest and most diverse group of specialized channels in nature, due to the large number of different insect species. And yet, we knew so little about these proteins,” Ruta said. Ruta and colleagues unveiled the structure of a protein for insect scent that provides an explanation for how insects evolved millions of odor receptors suited for a wide range of lifestyles and habitats.

Each insect olfactory unit is a channel comprised of two different proteins: an odor receptor that is opened by a specific scent molecule, and a co-receptor named Orco. While the odor receptors are highly specific to each species of insect, Orco is nearly the same in all of them. “You can take an Orco from one insect and it works with any other insect’s odor receptor,” explains Ruta. How one Orco assembles with hundreds of thousands of odor receptors was a fascinating evolutionary and molecular puzzle for Ruta, and she wanted to look at it in greater detail.

Using cryo-, Ruta and colleagues solved Orco’s structure, which serves as the first structural template to understand this huge protein family. “Orco itself can form an ion channel, unlike any others,” said Ruta. It features a central pore surrounded by four loosely-associated subunits, which explains how it can assemble with so many different odor receptors. “By minimizing inter-subunit interactions, it’s able to accommodate many ,” Ruta explained, they believe it can assemble with an odor receptor and share a common channel. Orco’s shape may also be crucial for evolution.

When Ruta mapped the sequence of onto the Orco channel the similarity was strong in pore, but weak in the four loosely-associated subunits, which may allow those parts to diversify and evolve rapidly. Orco also likely provides a channel that works no matter how much the receptor diversifies, since they assemble together.

Most rely heavily on smells to navigate the world. And when it comes to insect vectors of disease, like mosquitoes, Ruta says, “this could be a starting point for designing or insect confusants, that scramble the olfactory code and prevent them from finding their human hosts.”


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Structure of ion channel reveals how insects smell their way around the world


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Freshwater insects recover while spiders decline in UK

Date:
February 17, 2020
Source:
University College London
Summary:
Many insects, mosses and lichens in the UK are bucking the trend of biodiversity loss, according to a comprehensive analysis of over 5,000 species.
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Many insects, mosses and lichens in the UK are bucking the trend of biodiversity loss, according to a comprehensive analysis of over 5,000 species led by UCL and the UK Centre for Ecology & Hydrology (UKCEH).

The researchers say their findings on UK biodiversity between 1970 and 2015, published in Nature Ecology & Evolution, may provide evidence that efforts to improve air and water quality could be paying off.

“By looking at long-term trends in the distribution of understudied species, we found evidence of concerning declines, but we also found that it’s not all bad news. Some groups of species, particularly freshwater insects, appear to be undergoing a strong recovery,” said the study’s lead author, Dr Charlie Outhwaite (UCL Centre for Biodiversity & Environment Research, UK Centre for Ecology & Hydrology, and the RSPB).

Funded by the Natural Environment Research Council (NERC), the researchers analysed trends in the distribution of invertebrates (such as insects and spiders), bryophytes (such as mosses) and lichens over a 45-year period, to see whether they were following the same declining trends reported in better-studied groups such as mammals, birds and butterflies.

Across all 5,214 species surveyed, overall occupancy (distribution) was 11% higher in 2015 than in 1970. The researchers were not able to estimate the total numbers of each species, but gauged how well each species was doing by whether its geographic range was expanding or shrinking.

They found substantial variation between the different groups, and between individual species within each group. Among the four major groups studied, only one of them — terrestrial non-insect invertebrates (mainly spiders, centipedes and millipedes) — exhibited an overall trend of declining distribution (by 7% since 1970).

More positively, freshwater insects, such as mayflies, dragonflies and caddisflies, have undergone a strong recovery since the mid-1990s, recently surpassing 1970 levels following a 47% decline from 1970 to 1994. Mosses and lichens have also increased in average occupancy (distribution) by 36%, while terrestrial insects, such as ants and moths, exhibited a slight increase.

The data included over 24 million records, each identifying a sighting of a particular species in a particular location, sourced from numerous biological recording schemes. People from across the UK have been contributing to the recording schemes on a volunteer basis for decades.

While the volunteers used inconsistent methods to collect their records, having such a vast quantity of data enabled the researchers to analyse it effectively using occupancy modelling techniques.

“Our study demonstrates the power of citizen science, as anyone can contribute to impactful academic research. We couldn’t have done this research without the hard work of thousands of volunteers who have contributed to recording schemes over the years,” said Dr Outhwaite.

While the study period only went back to 1970, other research suggests that many of the species studied would have been experiencing long-term declines dating back to the industrial revolution or further, due to pollution or habitat losses from agricultural expansion and urbanisation.

While they did not investigate the particular reasons for the declines and recoveries found in this study, the researchers say that it’s likely that environmental protection initiatives are helping some species recover. Mosses and lichens are known to be susceptible to air pollution, while freshwater insects likely benefited from improvements in waste water treatment since the early 1990s.


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Materials provided by University College London. Note: Content may be edited for style and length.


Journal Reference:

  1. Charlotte L. Outhwaite, Richard D. Gregory, Richard E. Chandler, Ben Collen, Nick J. B. Isaac. Complex long-term biodiversity change among invertebrates, bryophytes and lichens. Nature Ecology & Evolution, 2020; DOI: 10.1038/s41559-020-1111-z

Phys.Org


Bacteria get free lunch with butterflies and dragonflies

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A caterpillar of the Plain Tiger butterfly (Danaus chrysippus) crawls on a leaf of its host plant Calotropis gigantia, sprawling with bacteria and fungi. The leaf was incubated with nutrient-rich media to unravel the magnificent microbial diversity in larval diet. Credit: Kruttika Phalnikar and Shoot for Science

For humans, trade is second nature and civilizations have flourished and fallen with the fate of their trade. In fact, the mutual scratching of backs is a cornerstone of many animal societies. On the other hand, deep and sustained mutualisms across species were long thought to be quirks of evolution, where radically different players managed to stick together and trade for mutual benefit. Famous examples include mitochondria (ex-bacterial cells), which are embedded in and power animal and plant cells. These ancient mutualisms are incredibly fascinating; for how could such delicate relationships survive the travails of time and evolution?

In the past two decades, new genetic tools to find and identify microbes have upended the notion of rare mutualisms. It turns out that most animals and plants house complex and structured microbial communities, providing them food, safety, and even passage to new hosts. What’s more, the microbes pay rent! Some manufacture enzymes or vitamins for their hosts, while others take care of toxins and enemies. The currency is varied and rich, with hundreds of examples of fascinating mutualisms. Especially in insects, such associations are so common that they are proposed to have driven the incredible diversification of insects across the earth.

Against this backdrop of rampant , recent work from Deepa Agashe’s group at NCBS presents a jarring contrast. Her team found that unlike other insects, neither butterflies nor seem to have evolved strong mutualisms with their bacterial guests. Instead, bacteria seem to be transient acquaintances, sampled randomly from species encountered in the diet or environment.

The case of dragonflies is interesting, because they are thought to be generalist predators of aquatic ecosystems. Their protein-rich diet could perhaps be more easily digested with the help of bacterial enzymes. Postdoctoral fellow Rittik Deb and project assistant Ashwin Nair dissected the guts of many dragonflies, and used genetic tools to identify the bacterial residents and insect prey. Strong host-bacterial mutualisms should lead to consistent and similar bacterial communities across individual hosts. Instead, the team found that dragonflies with more diverse diets also housed varied bacterial communities. The work also provided some of the first evidence that dragonflies are not generalist predators. Different dragonfly species—even those living by the same pond on the NCBS campus—specialize on different insect prey, acquiring different bacteria in the process.

Most butterfly caterpillars also only eat specific plants. Ph.D. student Kruttika Phalnikar thus expected that different butterflies should have tailored mutualisms with different bacteria. But as they mature into adults, leaf-eating caterpillars transition to sipping nectar, which should entail a dramatic shift in the bacterial community. Collaborating with butterfly expert Krushnamegh Kunte, Phalnikar analysed bacterial communities from several wild-caught butterflies. Surprisingly, she found similar bacteria on plant leaves; in caterpillars that ate the leaves; and in mature adult butterflies. Caterpillars of different species also housed more similar bacteria than expected. Parallel results from an independent study in the neotropics indicated that butterflies may generally lack a stable microbiome.

Could we go a step further with this idea? Unlike dragonflies, butterflies can be reared in a greenhouse, and the team could directly test whether losing bacterial communities was costly. Using antibiotics, Phalnikar killed bacteria found in the caterpillars of two butterfly species. Indeed, the caterpillars developed just as well as control (unmanipulated) larvae. Even when she added fecal microbes back into the diet, caterpillar growth and survival was unaffected. Thus, butterflies do not seem to rely on bacteria to digest toxins in their food plants, or to acquire essential nutrients.

Together, these studies suggest a remarkable independence from bacterial mutualists in two very different insect groups. On the one hand this is puzzling, because establishing alliances is a very powerful (and oft-used) way to get ahead in life. The spectacular diversification of butterflies (India alone has ~1400 species) is also associated with the ability to eat a wide range of plants; many of which are toxic, difficult to digest, or offer poor nutrition. It seems incredible that butterflies managed to colonize all these niches on their own. On the other hand, it is not easy to find good partners, and even harder to maintain long-term relationships. Co-dependence is fraught with danger: partners may drift apart, go extinct, or turn on each other. We thus circle back to the idea that mutualisms should be rare.

These results open up new and exciting questions. How do butterflies and dragonflies manage without bacterial help? How did other insects successfully negotiate the pitfalls of co-dependence? More generally, can we predict when symbiosis will succeed? The wide spectrum of insect-bacterial mutualisms offers a unique opportunity to understand how trade partnerships establish, evolve, and dissolve over time.


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Butterflies can acquire new scent preferences and pass them on to their offspring


More information: Kruttika Phalnikar et al, Disrupting butterfly caterpillar microbiomes does not impact their survival and development, Proceedings of the Royal Society B: Biological Sciences (2019). DOI: 10.1098/rspb.2019.2438

Provided by National Centre for Biological Sciences