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Robotic weed removal eliminates need for expensive hand crews

TAGS: TECHNOLOGYTodd FitchetteFarmWise weederSingle-

Single-line organic cauliflower is weeded with a robot developed and operated by the Salinas-based FarmWise.FarmWise offers a business model that provides weeding services, freeing the grower from having to own and maintain a machine.

Todd Fitchette | Dec 04, 2020

Produce growers in Arizona and California are being introduced to the futuristic world of George Jetson as robots and artificial intelligence replace labor crews used to rogue weeds from lettuce, cauliflower, and other vegetable crops.

Salinas, Calif.-based FarmWise is a service company with a robotic weeding machine capable of rouging weeds at speeds of one-to-two miles per hour. This eliminates the need for expensive hand crews or chemical herbicides.

The FarmWise weeding machine is part of a service FarmWise provides. Unlike some companies that sell the machines, FarmWise offers a business model that provides weeding services, freeing the grower from having to own and maintain a machine.

The Titan FT35 is the third generation of machines developed by FarmWise. Company Chief Executive Officer Sebastien Boyer said testing on previous generations of machine took place over the past several years. The newest generation of machine is being used commercially in California and Arizona. https://c8c1c3523498a4e6800111cf107f6155.safeframe.googlesyndication.com/safeframe/1-0-37/html/container.html

The machine uses artificial intelligence to learn the various crops by studying the plant structure, according to Sal Espinoza, regional manager with FarmWise. Once the computer successfully learns the stem structure of the produce plant, the ability to cull weeds is simple. This process can take a few months of machine learning to get it right, Boyer said.

The machines can be outfitted with as many as six weeders. These are the rows of internal components that contain the metal knives that cut through the soil and rogue weeds as cameras track the vegetation and the AI of the onboard computer determines whether the plants are the planted produce, or weeds.

Boyer said his long-term goal is to find additional ways to mechanize the manual labor and tedious tasks performed by human hands. Through the machine learning the AI can distinguish cauliflower, celery, broccoli, and cabbage. Other crops including tomatoes and pepper are being perfected.

The company’s current business model is focused on providing services to produce growers in the desert region of southern California and Arizona after an inaugural run in the Salinas Valley. Boyer said he is also looking at European markets to expand his machine weeding technology.

Aphelenchoides besseyi

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EPPO Datasheet: Aphelenchoides besseyi

Last updated: 2020-07-24

IDENTITY

Preferred name:Aphelenchoides besseyi
Authority: Christie
Taxonomic position: Animalia: Nematoda: Chromadorea: Rhabditida: Aphelenchoididae
Other scientific names: Aphelenchoides oryzae Yokoo, Asteroaphelenchoides besseyi (Christie) Drozdovski
Common names in English: rice leaf nematode, rice white-tip nematode, strawberry crimp disease nematode, white-tip nematode
view more common names online…
Notes on taxonomy and nomenclature

The taxonomy used in this datasheet reflects developments suggested by several recent publications, summarised in Decraemer & Hunt (2013), which place Aphelenchoides in the Order Rhabditida, Suborder Tylenchina. This contrasts with the taxonomy nomenclature occasionally used by some authors (such as the CABI Invasive Species Compendium CABI, 2019; Wheeler & Crow, 2020), which place Aphelenchoides in the Order Aphelenchida, Suborder Aphelenchina (Hunt, 1993). Whilst this makes no difference to classification from the level of Superfamily (Aphelenchoidea) to species level (Aphelenchoides besseyi), those studying the species might need to be aware of differences in the literature.EPPO Categorization: A2 list
EU Categorization: RNQP (Annex IV)
view more categorizations online…
EPPO Code: APLOBE HOSTS 2020-07-24 GEOGRAPHICAL DISTRIBUTION 2020-07-24 BIOLOGY 2020-07-24 DETECTION AND IDENTIFICATION 2020-07-24 PATHWAYS FOR MOVEMENT 2020-07-24 PEST SIGNIFICANCE 2020-07-24 PHYTOSANITARY MEASURES 2020-07-24 REFERENCES 2020-07-24 ACKNOWLEDGEMENTS 2020-07-24 How to cite this datasheet? Datasheet history 2020-07-24

University of Bristol

Animals fake death for long periods to escape predators

1-Mar-2021 10:00 AM EST, by University of Bristolfavorite_border

Newswise: Animals fake death for long periods to escape predators

Nigel R. Franks

European antlion (Euroleon nostras) on its dorsal side playing dead.

Embargoed until 00.01hrs UK time on Wednesday 3 March 2021

Newswise — Many animals feign death to try to escape their predators, with some individuals in prey species remaining motionless, if in danger, for extended lengths of time.

Charles Darwin recorded a beetle that remained stationary for 23 minutes – however the University of Bristol has documented an individual antlion larvae pretending to be dead for an astonishing 61 minutes. Of equal importance, the amount of time that an individual remains motionless is not only long but unpredictable. This means that a predator will be unable to predict when a potential prey item will move again, attract attention, and become a meal.

Predators are hungry and cannot wait indefinitely. Similarly, prey may be losing opportunities to get on with their lives if they remain motionless for too long. Thus, death-feigning might best be thought of as part of a deadly game of hide and seek in which prey might gain most by feigning death if alternative victims are readily available.

The study, published today in science journal Biology Letters, involved evaluating the benefits of death-feigning in terms of a predator visiting small populations of conspicuous prey. Researchers used computer simulations that utilise the marginal value theorem, a classical model in optimization.

Lead author of the paper Professor Nigel R. Franks from the University of Bristol’s School of Biological Sciences, said: “Imagine you are in a garden full of identical soft fruit bushes. You go to the first bush. Initially collecting and consuming fruit is fast and easy, but as you strip the bush finding more fruit gets harder and harder and more time consuming.

“At some stage, you should decide to go to another bush and begin again. You are greedy and you want to eat as many fruit as quickly as possible. The marginal value theorem would tell you how long to spend at each bush given that time will also be lost moving to the next bush.

“We use this approach to consider a small bird visiting patches of conspicuous antlion pits and show that antlion larvae that waste some of the predator’s time, by ‘playing dead’ if they are dropped, change the game significantly. In a sense, they encourage the predator to search elsewhere.”

The modelling suggests that antlion larvae would not gain significantly if they remained motionless for even longer than they actually do. This suggests that in this arms race between predators and prey, death-feigning has been prolonged to such an extent that it can hardly be bettered.

Professor Franks added: “Thus, playing dead is rather like a conjuring trick. Magicians distract an audience from seeing their sleights of hand by encouraging them to look elsewhere. Just so with the antlion larvae playing dead – the predator looks elsewhere. Playing dead seems to be a very good way to stay alive.”

Paper:

‘Hide-and-seek strategies and post-contact immobility’ by NR Franks, A Worley and AB Sendova-Franks in Biology Letters

Image:

European antlion (Euroleon nostras) on its dorsal side playing dead. Credit: Nigel R. Franks

https://fluff.bris.ac.uk/fluff/u1/hu21584/gouW2eLlMqxEzBsRwNZxGAzcJ/

Issued on Monday 1 March 2021 by University of Bristol Media and PR Team. For more information email press-office@bristol.ac.uk.

Here’s How Insects Coax Plants into Making Galls

24-Feb-2021 10:20 AM EST, by Howard Hughes Medical Institute (HHMI)1favorite_border

Newswise: Here’s How Insects Coax Plants into Making Galls

David Stern

Hormaphis cornu aphids feed on witch hazel leaves and coax the plants into making galls.

Newswise — Insects can reprogram plant growth, transforming ordinary plant parts into intricately patterned shelters that are safe havens for feeding and reproduction.

These structures, called galls, have fascinated biologists for centuries. They’re crafted by a variety of insects, including some species of aphids, mites, and wasps. And they take on innumerable forms, each specific in shape and size to the insect species that’s created it – from knobs to cone-shaped protrusions to long, thin spikes. Some even resemble flowers.  

Insects create galls by manipulating the development of plants, but figuring out exactly how they perform this feat “feels like one of the great unsolved problems in biology,” says David Stern, a group leader at the Howard Hughes Medical Institute’s Janelia Research Campus. “How does an organism of one kingdom take control of the genome of an organism in another kingdom to completely reorganize its development, to produce a home for itself?”

Now, Stern and his colleagues have identified the first examples of insect genes that directly guide gall development. These genes are turned on in aphids’ salivary glands and appear to direct gall formation when the insects spit their saliva into the plants. One gene the team identified determines whether such galls will be red or green, the researchers report in a paper published March 2, 2021 in Current Biology.

“I think they’ve discovered essentially new territory,” says Patrick Abbot, a molecular ecologist at Vanderbilt University who wasn’t involved in the work. There’s a strong likelihood that similar genes are found in other insects, he says. “It makes me want to run to the lab and start looking back through my data.”

Figuring out how to study gall formation has been a longstanding challenge, Stern says – one that’s interested him since he was a graduate student doing fieldwork in Malaysia. Gall-making insects aren’t laboratory model organisms like fruit flies, and not as much is known about their genetics.

A few years ago, while wandering the woods of Janelia’s riverside campus, Stern made a convenient observation. Hormaphis cornu aphids make galls on witch hazel trees, small flowering trees that are abundant on campus. Even on a single leaf, Stern noticed, some Hormaphisaphids were making green galls, while others were making red ones. It set up a natural experiment – a chance to compare two visibly distinct kinds of galls and figure out what’s genetically different between the aphids that make them.

When Stern and his team sequenced the genomes of aphids that made green galls and those that made red galls, they pinpointed a gene that varied between the two genomes. Aphids with one version of a gene that they named “determinant of gall color” made green galls; aphids with a different version made red ones. The finding piqued their curiosity, as the gene didn’t look like any previously identified genes.

To dive deeper, they collected aphids from both witch hazel trees and river birch trees. (Hormaphis cornu aphids live on river birch trees in the summer, but don’t make galls there.) Back in the lab, the researchers carefully dissected out the insects’ tiny salivary glands. In these glands, the team hunted for genes that were turned on only in the aphids that made galls. The researchers found that the gene determinant of gall color was similar to hundreds of other genes that were all turned on specifically in the gall forming aphids. Stern’s team dubbed this group bicycle genes.

The gall-making aphids on the witch hazel trees switch on these genes to make BICYCLE proteins. The insects might spit these proteins into plant cells to reprogram leaf tissue into making a gall instead of normal plant parts, says Aishwarya Korgaonkar, a research scientist in the Stern lab who helped lead the project.

“This is a beautiful bit of biology,” says Sam Mugford, a plant scientist at the John Innes Center in Norwich, England who wasn’t involved in the research. “The exciting work ahead will be to understand the molecular processes that are going on inside the plant when the proteins are delivered by the aphid.”

The team is now working to identify the plant molecules targeted by the aphids’ BICYCLE proteins, says Korgaonkar. That could help them understand just how BICYCLE proteins goad plants into forming galls.

“After years of wondering what’s going on, it’s very rewarding to have something to show for it,” Stern says.

FEBRUARY 25, 2021

Global change alters microbial life in soils—and thereby its ecological functions

by German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig

soil
Credit: CC0 Public Domain

Soil microorganisms play a critical role in the survival of life-sustaining ecosystems and, consequently, human well-being. Global assessments continue to provide strong evidence that humans are causing unprecedented biodiversity losses. However, existing information is strongly biased towards selected groups of vertebrates and plants, while much less is known about potential shifts in below ground communities.

Soil microbial communities are largely an unseen majority, even though, according to first author Dr. Carlos Guerra (iDiv, MLU), “they control a wide range of ecosystem functions that have implications for both human well-being and the sustainability of our ecosystems.” The published results provide evidence that climate change has a stronger influence on soil microbial communities than land-use change like deforestation and agricultural expansion.

The scientists focused especially on bacteria and fungi, which are the most diverse groups of soil-dwelling organisms across the globe. They studied a comprehensive database of soil microbial communities across six continents, whilst incorporating temperature, precipitation and vegetation cover data. Established climate and land-use projection datasets were used to compute various temporal change scenarios, based on a projection period from 1950 to 2090. To understand this complex system with multiple interdependent variables, four structural equation models were developed for bacterial richness, community dissimilarity, phosphate transport genes and ecological clusters. These models are particularly useful for distinguishing between the direct and indirect effects of external environmental variables (vegetation type, temperature, precipitation, etc.) on the aforementioned biodiversity variables.

The authors were able to show that local bacterial richness will increase in all scenarios of climate and land-use change considered. Although this increase will be followed by a generalized community homogenisation process affecting more than 85% of terrestrial ecosystems. Scientists also expect changes in the relative abundance of functional genes to accompany increases in bacterial richness. These could affect soil phosphorus uptake, which in turn could limit plant and microbial production. The results of the ecological cluster analysis suggest that certain bacteria and fungi known to include important human pathogens, major producers of antibiotic resistance genes, or potential fungal-transmitted plant pathogens will become more abundant.

While increases in local microbial diversity might seem positive at first glance, they hide strong reductions in community complexity in the majority of terrestrial systems, with implications for ecosystem functioning. Future ecosystems are therefore expected to have a greater number of bacterial lineage communities at the local scale, making several bacterial species groups potentially more abundant in soil communities under global change scenarios. Assuming the links between functionality and taxonomy remain constant through time, this suggests that similar bacterial groups with similar functional capabilities will live in soils across the globe, reducing specialization and potentially the adaptation capacity of ecosystems to new environmental realities.

The published results are at odds with current global projections of aboveground biodiversity declines, but do not necessarily provide a more positive view of nature’s future. Major changes in microbial diversity driven by climate and land-use change have significant implications for ecosystem functioning. “The results also help to fill an important gap identified in current global assessments and agreements,” says group leader Prof Nico Eisenhauer (iDiv, UL). They also lay the groundwork for incorporating soil organisms into future assessments of ecosystem response to global change drivers. According to mathematician Dr. Eliana Duarte (MiS), “the application of mathematical and statistical methods to the study of the soil microbiome will play an increasingly important role as more data on soils becomes available.”


Explore further Research delineates the impacts of climate warming on microbial network interactions


More information: Carlos A. Guerra et al, Global projections of the soil microbiome in the Anthropocene, Global Ecology and Biogeography (2021). DOI: 10.1111/geb.13273Journal information:Global Ecology and BiogeographyProvided by German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig

Relationship between Nitrogen and crop disease

  1. The Crescent News
  2. By Hoorman Soil Health Services
  3. Feb 25, 2021 Updated Feb 25, 2021
  4.  

Nitrogen (N) is the fourth most abundant plant nutrient with about 80-85% N sequestered in protein, 10% in genetic components (DNA & RNA), and 5% in amino acids (protein building blocks). Nitrogen makes proteins like enzymes (speed up chemical reactions), hormones (regulate plant functions), and N increases cell growth. Nitrogen strengthens plant cell walls (cellulose), is used in plant energy transfer (ATP), and in photosynthesis (chlorophyll); effecting many plant processes. If a plant has balanced N, it has less disease; but when N is either deficient or in excess, expect more disease and insect problems in the field, garden, with ornamentals, or house plants.https://e58b06d6ddf80758d88dccc3cc17f20d.safeframe.googlesyndication.com/safeframe/1-0-37/html/container.html

The rate of N application and the form depends on the plant’s life cycle. Nitrogen deficiency or excess N may change the cell wall to become leaky, promoting more diseases. Early on, plants need more nitrates for growth with ammonium sources increasing as the plant matures to increase yield. N stressed deficient plants can’t make full proteins while excess N lowers plant defenses to both disease and insects. Plants typically absorb N in the oxidized form as nitrate (NO3-) or the reduced form as ammonium ( NH4+). Ammonium is 25% more plant efficient than nitrates because it can be easily converted to amino acids but to avoid toxicity, plants need it in small doses and it is easily converted to soil nitrate. Soil health keeps these N forms plant available to optimize plant growth and yield.

Nitrogen interacts with many other plant nutrients. Potassium (K) promotes the increase of nitrates and plant growth, but too much K decreases yield. Adequate phosphorous plus chlorine decreases nitrates and enhances plant ammonium N forms to increase yield. In soybeans, calcium and cobalt are needed for Rhizobium microbes to fix atmospheric N into protein. Supplementing cobalt (a micronutrient) and calcium in soybeans at the right time may increase soybean yields by 3x. Molybdenum, manganese, iron, and magnesium are involved in nitrogen transformations and protein synthesis. As my high school math teacher (Dave Laudick) use to say: It’s as clear as mud. Soil organic matter is a storehouse of many essential micronutrients and allows soil microbes and plants to thrive in a buffered and safe environment. Yes, it’s complicated but worth knowing if yields improve.

Common N related corn diseases are gray leaf spot, stalk rot due to late season N stress (N deficient), and increased aflatoxin due to high nitrates. In soybeans, to much N increases mosaic virus and Rhizoctonia. In wheat, take-all is increased by nitrates, decreased by ammonium; too much N increased powdery mildew; but higher N levels decreases Stagonospora nodurum. Balanced N fertilization is a key to decreasing most diseases.

Time of N fertilization is important. Corn side dressing reduces N leaching and denitrification losses but also decreases Pythium and Rhizoctonia BUT may increase Fusarium and Gibberella stalk rot. Adding a N inhibitor to fertilizer or liquid manure may decrease corn stalk rot by keeping N in the ammonium form late season. In soybeans, avoid over using glyphosate because it chelates or ties up manganese, iron, calcium, and zinc which can affect plant N fixation. In wheat, delaying N fertilizer until spring promotes take-all but avoids excess winter N when its cold and wet, so less Rhizoctonia. Best solution, put on a small amount of N in fall to promote tillering and delay spring N applications until late spring using granular or urea forms of N to reduce foliar leaf stress from liquid N sources.

There are four strategies to reducing diseases associated with nitrogen. The 4 R’s are the right form, right time, right rate, and right place. Use a balanced N fertilizer program with sufficient N in the right form for optimum growth. For corn starter, 25% nitrates and 75% ammonium, is a good mix but placement (2”X2”, 2”X4”) is critical to avoid root stress. Weather, pH, soil conditions (compaction), soil texture, moisture, biological activity, etc. all affect N transformations and plant uptake. Building SOM buffers soils and helps control or moderate these factors. Make timely N applications to avoid N deficiency, excesses, or losses. Modify the soil environment by changing pH (lime), add cover crops to build soil organic matter, reduce soil compaction, add a N inhibitor, avoid over using glyphosate, or supplement with micronutrients to assist in optimal N utilization and less crop disease. Source: Mineral Nutrition and Plant Disease, 2018.

Insects silencing the alarm

An enzyme in the saliva of certain insects prevents their food plants from warning neighboring plants of an attack

Date: February 17, 2021 Source:Penn State

Summary:Like a scene from a horror movie, tomato fruitworm caterpillars silence their food plants’ cries for help as they devour their leaves. That is the finding of a multidisciplinary team of researchers, who said the results may yield insights into the abilities of crop plants — such as tomato and soybean — to withstand additional stressors, like climate change.Share:    FULL STORY


Like a scene from a horror movie, tomato fruitworm caterpillars silence their food plants’ cries for help as they devour their leaves. That is the finding of a multidisciplinary team of researchers, who said the results may yield insights into the abilities of crop plants — such as tomato and soybean — to withstand additional stressors, like climate change.

“We have discovered a new strategy whereby an insect uses saliva to inhibit the release of airborne plant defenses through direct manipulation of plant stomata,” said Gary Felton, professor and head of the Department of Entomology at Penn State, noting that stomata are tiny pores on plant leaves that regulate gas exchange, including plant defensive emissions and carbon dioxide, between the plant and the environment.

Specifically, the researchers studied the effects of a particular enzyme — glucose oxidase (GOX) — that occurs in the saliva of tomato fruitworm caterpillars (Helicoverpa zea) on plant stomata and plant defensive emissions, called herbivore-induced plant volatiles (HIPV).

“HIPVs are thought to help protect plants from insect herbivores by attracting natural enemies of those herbivores and by alerting neighboring plants to the presence of herbivores nearby,” Felton said. “Consequently, stomatal closure has the potential to alter interactions across the entire plant community.”

In their experiments, the researchers used CRISPR/Cas9, a technique for editing genomes, to produce caterpillars that lack the GOX enzyme. In separate glass chambers fitted with filter traps to collect HIPVs, they allowed the caterpillars with the non-functional enzyme, along with unmanipulated caterpillars, to feed on tomato, soybean and cotton plants for three hours. To examine the stomatal response to GOX, the team examined the plant leaves under a microscope and measured the size of the stomatal openings. Next, they extracted the volatile compounds from the filter traps and used gas chromatography, coupled with mass spectrometry, to identify and quantify the HIPVs.

“This study is the first to use CRISPR/Cas9-mediated gene editing to study the function of an insect salivary enzyme,” said Po-An Lin, a graduate student in entomology at Penn State and the lead author of the paper. “Using pharmacological, molecular, and physiological approaches, we were able to show that this salivary enzyme plays a key role in insect-induced stomatal closure and likely the reduction of several important defensive emissions.”

Indeed, the team — comprising experts in molecular biology, chemical ecology, plant physiology and entomology — found that GOX, secreted by the caterpillar onto leaves, causes stomatal closure in tomato plants within five minutes, and in both tomato and soybean plants for at least 48 hours. They also found that GOX inhibits the emission of several HIPVs during feeding, including (Z)-3-hexenol, (Z)-jasmone and (Z)-3-hexenyl acetate, which are important airborne signals in plant defenses. Interestingly, they did not find an effect of GOX on the cotton plants, which, the team said, suggests that the impacts of GOX on stomatal conductance is species dependent.

The team’s results appeared in the Jan. 18 issue of New Phytologist.

Lin noted that the fact that tomato fruitworm caterpillars evolved a salivary enzyme that inhibits emissions of defensive volatiles in certain species suggests the importance of plant airborne defenses in the evolution of insect herbivores.

“Given the ubiquity of HIPVs in plants, it is likely that traits which influence HIPVs have evolved broadly among insect herbivores,” he said.

Not only do these insects damage individual plants, but they also may render them less able to withstand climate change.

“Stomata are important organs of plants that not only detect and respond to environmental stressors, but also play a central role in plant growth,” said Felton. “Because stomata play an important role in regulating leaf temperature and leaf water content, our findings suggest that the control of stomatal opening by an insect could impact the plant’s response to elevated temperatures occurring with climate change and response to water deficiency.”

Other Penn State authors on the paper include Yintong Chen, graduate student in molecular, cellular and integrative biosciences; Chan Chin Heu, a former postdoctoral researcher; Nursyafiqi Bin Zainuddin, graduate student in entomology; Jagdeep Singh Sidhu, graduate student in horticulture; Michelle Peiffer, research support assistant in entomology; Ching-Wen Tan, postdoctoral scholar in entomology; Jared Ali, assistant professor of entomology; Jason L. Rasgon, professor of entomology and disease epidemiology; Jonathan Lynch, Distinguished Professor of Plant Science; and Charles T. Anderson, associate professor of biology. Also on the paper are Duverney Chaverra-Rodriguez, postdoctoral scholar, University of California, San Diego; Anjel Helms, assistant professor of chemical ecology, Texas A&M University; and Donghun Kim, assistant professor, Kyungpook National University.

The National Science Foundation, Agricultural and Food Research Initiative Program of the United States Department of Agriculture and a Hatch Project Grant supported this research.


Story Source:

Materials provided by Penn State. Original written by Sara LaJeunesse. Note: Content may be edited for style and length.


Journal Reference:

  1. Po‐An Lin, Yintong Chen, Duverney Chaverra‐Rodriguez, Chan Chin Heu, Nursyafiqi Bin Zainuddin, Jagdeep Singh Sidhu, Michelle Peiffer, Ching‐Wen Tan, Anjel Helms, Donghun Kim, Jared Ali, Jason L. Rasgon, Jonathan Lynch, Charles T. Anderson, Gary W. Felton. Silencing the alarm: an insect salivary enzyme closes plant stomata and inhibits volatile releaseNew Phytologist, 2021; DOI: 10.1111/nph.17214

Plant evolution driven by interactions with symbiotic and pathogenic microbes

Science
https://science.sciencemag.org/content/371/6531/eaba6605.full

From PestNet

Authors: Pierre-Marc Delaux and Sebastian Schornack

Abstract

During 450 million years of diversification on land, plants and microbes have evolved together. This is reflected in today’s continuum of associations, ranging from parasitism to mutualism. Through phylogenetics, cell biology, and reverse genetics extending beyond flowering plants into bryophytes, scientists have started to unravel the genetic basis and evolutionary trajectories of plant-microbe associations. Protection against pathogens and support of beneficial, symbiotic, microorganisms are sustained by a blend of conserved and clade-specific plant mechanisms evolving at different speeds. We propose that symbiosis consistently emerges from the co-option of protection mechanisms and general cell biology principles. Exploring and harnessing the diversity of molecular mechanisms used in nonflowering plant-microbe interactions may extend the possibilities for engineering symbiosis-competent and pathogen-resilient crops.

Read on: https://science.sciencemag.org/content/371/6531/eaba6605.full


From PestNet

FEBRUARY 17, 2021

Neonicotinoid pesticide residues found in Irish honey

by Thomas Deane, Trinity College Dublin

honey
Credit: CC0 Public Domain

Researchers from Trinity and Dublin City University found that Irish honey contained residues of neonicotinoid insecticides.

Neonicotinoids are the most widely used group of insecticides globally, used in plant protection products to control harmful insects.

Neonicotinoids are systemic pesticides. Unlike contact pesticides, which remain on the surface of the treated parts of plants (e.g. leaves), systemic pesticides are taken up by the plant and transported throughout its leaves, flowers, roots and stems, as well as incorporated into pollen and nectar.

In the European Union, their use is now restricted due to concerns about risks to bees and other non-target organisms. At the time of sampling for this study, their use was still approved in Ireland for certain agricultural crops.

Key findings

  • Of 30 honey samples tested, 70% contained at least one neonicotinoid compound
  • Almost half (48%) the samples contained at least two neonicotinoids
  • Exposure to pesticides does not just occur in agricultural settings
  • This research for the first time has identified the presence of clothianidin, imidacloprid and thiacloprid in Irish honey from a range of hive sites across a range of land use types
  • The proportion and concentration of neonicotinoids in honeys from both agricultural and urban habitats, compared with semi-natural or other land covers, suggests that exposure of bees to neonicotinoids can potentially occur in a variety of environments

Residue levels were below the admissible limits for human consumption according to current EU regulations, and thus pose no risk to human health.

However, the average concentration of one compound (imidacloprid) was higher than concentrations that have been shown in other studies to induce negative effects on honey and bumble bees.

Dr. Saorla Kavanagh, lead author on the study, currently working at the National Biodiversity Data Centre, said: “Given that these compounds have been shown to have adverse effects on honey bees, wild bees, and other organisms, their detection in honey is of concern, and potential contamination routes should be explored further.”

Professor Jane Stout, from Trinity’s School of Natural Sciences, said: “These results suggest that bees and other beneficial insects are at risk of exposure to contaminants in their food across a range of managed habitats—not just in agricultural settings. And even though we found residues at low concentrations, prolonged exposure to sublethal levels of toxins can cause effects that are still not fully understood by scientists or regulators. Therefore, we shouldn’t relax restrictions on their use.”

Dr. Blánaid White, DCU, said: “Our findings are consistent with others from outside Ireland, and neonicotinoids unfortunately seem to be ubiquitous in honeys worldwide. It’s reassuring that residues do not exceed safe levels, but it is an important warning that neonicotinoids should not be reintroduced into Irish environments, as they could potentially cause health or environmental concerns.”


Explore furtherOn balance, some neonicotinoid pesticides could benefit bees: study


Provided by Trinity College Dublin

Perceiving predators: Understanding how plants ‘sense’ herbivore attack

by Tokyo University of Science

Perceiving predators: Understanding how plants 'sense' herbivore attack
Recently, Professor Gen-ichiro Arimura from Tokyo University of Science, Japan, encapsulated the research on the herbivory-sensing mechanism of plants through elicitors. Commenting of the immense value of these elicitors, Prof. Arimura states, “This review focuses mainly on elicitors because they are timely, novel, and have potential biotechnological applications.” Credit: Gen-ichiro Arimura, Tokyo University of Science

Nature has its way of maintaining balance. This statement rightly holds true for plants that are eaten by herbivores—insects or even mammals. Interestingly, these plants do not just silently allow themselves to be consumed and destroyed; in fact, they have evolved a defense system to warn them of predator attacks and potentially even ward them off. The defense systems arise as a result of inner and outer cellular signaling in the plants, as well as ecological cues. Plants have developed several ways of sensing damage; a lot of these involve the sensing of various “elicitor” molecules produced by either the predator or the plants themselves and initiation of an “SOS signal” of sorts.

In a recently published review in the journal Trends in Plant Science, Professor Gen-ichiro Arimura from Tokyo University of Science, Japan, encapsulates the research on the herbivory-sensing mechanism of plants through elicitors. Commenting of the immense value of these elicitors, Prof. Arimura states, “This review focuses mainly on elicitors because they are timely, novel, and have potential biotechnological applications.”

When the same herbivorous animal comes to eat the plant multiple times, the plant learns to recognize its feeding behavior and records the “molecular pattern” associated with it. This is termed “herbivore-associated molecular patterns” or HAMPs. HAMPs are innate elicitors. Other plant elicitors include plant products present inside cells that leak out because of the damage caused by herbivory. Interestingly, when an herbivorous insect eats the plant, the digestion products of the plant cell walls and other cellular components become part of the oral secretions (OS) of the insect, which can also function as an elicitor!

Prof. Arimura highlights the fact that with the advancement of high-throughput gene- and protein-detecting systems, the characterization of elicitors of even specific and peculiar types of herbivores, such as those that suck cell sap and do not produce sufficient amounts of OS, has become possible. The proteins present in the salivary glands of such insects could be potential elicitors as they enter the plant during feeding. He explains, “RNA-seq and proteomic analyses of the salivary glands of sucking herbivores have led to the recent characterization of several elicitor proteins, including a mucin-like salivary protein and mite elicitor proteins, which serve as elicitors in the leaves of the host plants upon their secretion into plants during feeding.”

The review also highlights some peculiar elicitors like the eggs and pheromones of insects that plants can detect and initiate a defense response against. In some special cases, the symbiotic bacteria living inside the insect’s gut can also regulate the defense systems of the plants.

And now that we have understood different types of elicitors, the question remains—what signaling mechanisms do the plants use to communicate the SOS signal?

So far, it has been hypothesized that the signaling is made possible by proteins transported through the vascular tissue of plants. Interestingly, there is evidence of airborne signaling across plants, by a phenomenon called “talking plants.” Upon damage, plants release volatile chemicals into the air, which can be perceived by neighboring plants. There is also evidence of epigenetic regulation of defense systems wherein plants maintain a sort of ‘genetic memory’ of the insects that have attacked them and can fine-tune the defense response accordingly for future attacks.

Given the improvement in knowledge of the mechanisms of plant defense systems, we can embrace the possibility of a “genetic” form of pest control that can help us circumvent the use of chemical pesticides, which, with all their risks, have become a sort of “necessary evil” for farmers. This could usher in modern, scientifically sound ways of organic farming that would free agricultural practices from harmful chemicals.


Explore further How a molecular ‘alarm’ system protects plants from predators


More information: Gen-ichiro Arimura, Making Sense of the Way Plants Sense Herbivores, Trends in Plant Science (2020). DOI: 10.1016/j.tplants.2020.11.001Journal information:Trends in Plant Science Provided by Tokyo University of Science

Brisbane beekeeper creates editable map to track African tulip trees killing native stingless bees

From PestNet

ABC Radio Brisbane
https://www.abc.net.au/news/2021-02-17/beekeper-creates-tree-map-to-save-native-bees/13156240

By Antonia O’Flahert

A Brisbane beekeeper has created a map for the public to locate African tulip trees in a bid to weed out the plant, which kills native bees.

Hobbyist beekeeper Phil Baskerville told Steve Austin on ABC Radio Brisbane there was not an effective mapping system to report African tulip trees, so decided to create one on Google Maps.The tree is native to tropical Africa but was once planted as a street tree and garden tree, and while regarded for its red flowers, it is a serious weed which is toxic to native stingless bees and crowds out native vegetation.

“I’ve labelled it [the map] African Tulip Tree, people should be able to find that and they can actually drop a pin on every tree they identify,” Mr Baskerville said.

“It’s quite prevalent across fairly old suburbs, the inner 15-kilometre radius of those suburbs, they were prevalently planted as a street tree down a number of footpaths.”

Brisbane City Council stopped planting the trees 20 years ago, with about 2,000 older plants left, according to environment, park and sustainability chair Fiona Cunningham.

The exotic tree is a significant weed across coastal Queensland which is “highly invasive, forming dense stands in gullies and along streams, crowding out native vegetation”, according to Department of Agriculture and Fisheries information.

Read on: https://www.abc.net.au/news/2021-02-17/beekeper-creates-tree-map-to-save-native-bees/13156240


Sunday, 21 February 2021 03:49:05

From PestNet

Locust Hunters On a Mission in Kenya

africanews
https://www.africanews.com/2021/02/16/kenya-desert-locust-hunters-in-full-effect-to-control-infestation/

By Kizzi Asala with AFP

In light of the ongoing desert locust infestations in Kenya, the United Nations Food and Agriculture Organization (FAO) has teamed up with the company 51 Degrees to get control of the situation — via tracking software integrated with a hotline system, scouts and dispatched aircraft.

The software — initially developed for tracking poaching, injured wildlife and illegal logging and other conservation needs, has been reworked to instead trace and tackle locust swarms.

The hotline takes calls from village chiefs or some of the 3,000 trained locals scouts.

The aircrafts are then dispatched according to the data on the size of the swarms and direction of travel are shared with the pilots – as well as governments and organisations battling the invasion in Somalia, Kenya and Ethiopia.

Batian Craig, the Director of 51 Degrees, shared the company’s contribution.

“We’ve been part of the desert locusts surveying and controls side of things from January last year, you know, our approach is completely being changed by good data, by timely data, and by accurate data, and you know with that certainly for Kenya and this way we’ve stopped 80% getting back into the breadbasket where last year we were dealing with a very different situation.”

Desert Locust Storm in East Africa

Notoriously difficult to control and each eating its weight in vegetation daily, the ravenous desert locusts first infested the Eastern Horn of Africa region in mid-2019 — eventually invading nine countries as the area experienced one of its wettest and inopportune rainy seasons in decades.

Jane Gatumwa, a local farmer, hopes to an end to this dire situation.

“Before the locusts, we used to harvest 25 bags from an acre of maize but now we don’t expect to harvest anything this time around because they completely eat everything. Back then when there were no locusts we used to harvest 50 bags of potatoes, harvest 5 bags of beans per acre but now they have eaten everything there’s nothing we will harvest. The government needs to act swiftly and spray pesticides so that we can at least salvage the maize which is the only thing left, there’s nothing else left.”

Kenya had not seen the pest in up to 70 years and the initial response was hampered by poor coordination, plus lack of pesticides and aircrafts.

Second Wave Updated Approach

A slick new operation to combat a second wave of the pests has improved control and co-operation in Kenya, Ethiopia and parts of Somalia.

Cyril Ferrand, the FAO East Africa Resilience Team Leader, outlines the new methods to gain control of the problem.

“We have a lot of swarms, the swarms are much smaller and then the capacity to respond is much higher. So a year ago in February 2020, we had two aircrafts in Kenya able to spray a very very minimal quantity of pesticide. Now in Kenya, we have 10 aircrafts operating, so the time lap between the moment we can spot desert locust and the moment we can treat is much faster, which means that the damage also is very reduced on vegetation and biomass.”

In 2020, the locust infestation affected the food supply and livelihoods of some 2.5 million people — and 3.5 million could be impacted in 2021.