Feeds:
Posts
Comments

Archive for the ‘Control tactics’ Category

51327662659_84fbf3db6c_o.png

Fall armyworms eating rice leaves in a flooded field. Entomologists seek emergency-use exemption to help rice growers in ‘epic’ battle against armyworms.

Mary Hightower, U of A System Division of Agriculture | Jul 22, 2021SUGGESTED EVENT

Events Page - Farm Progress Show 2021

Farm Progress ShowAug 31, 2021 to Sep 02, 2021

University of Arkansas System Division of Agriculture entomologists are seeking an emergency exemption to allow for the use of Intrepid to help control armyworms that threaten the state’s 1.24 million acres of rice. 

“This is the biggest outbreak of fall armyworm situation that I’ve ever seen in my career,” Gus Lorenz, extension entomologist for the Division of Agriculture, said Wednesday. “They’re in pastures, rice, soybeans, grain sorghum. It’s epic.”https://d4100051ff2b64e2ac90e81feaf8c9c5.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

Lorenz said the Section 18 request to enable use of Intrepid should be submitted to the Arkansas State Plant Board by Friday.

Intrepid is a growth regulator that’s approved for use in just about every other row crop but is not labeled for use in rice.

“This armyworm thing started about three to four weeks ago,” he said. “It’s continued to build from that time. It’s from the Boot heel of Missouri down to Louisiana.”

Eaten to the ground

Gus Lorenz51326207237_6519faedbd_o.png

Sweep net full of armyworms. Taken July 21, 2021.Lorenz said he received a call from a producer in “south Arkansas, that they’d eaten his bermudagrass pasture to the ground. It was a 30- to 40-acre pasture. And he wasn’t even calling about the pasture. He was calling about his rice crop. He said his rice was being eaten to the ground.”

“Fall armyworm is a particularly voracious caterpillar,” said Jarrod Hardke, extension rice agronomist for the Division of Agriculture. “They have a tendency to surprise us because adults lay very large egg masses but the earliest instar larvae eat very little. It’s not until they get older and start to spread out that they consume most of the food in their life cycle.

“This is why we go from zero to TREAT seemingly overnight,” Hardke said.

Why a Section 18?

51327145063_f633537f6a_o.jpgExtension entomologist Nick Bateman examines a rice field in Jefferson County on July 21, 2021 for fall armyworms. (U of A System Kurt Beaty)

Typically, armyworms can be managed well using pyrethroids, but Lorenz said “when this outbreak first started, we got reports out of Texas and Louisiana that they weren’t getting control. We’re getting failures.”

Lorenz said he and colleagues ran some quick tests, spraying this year’s armyworms with pyrethroids “and we got 48% control.”

In cattle-heavy parts of the state producers use another insect growth regulator called Dimilin to manage armyworms, but in row crop country, “they just don’t carry it. It’s just not available,” Lorenz said.

Fellow extension entomologist Nick Bateman said, “another problem with using Dimilin is the pre-harvest interval. The pre-harvest interval on Dimilin is 80 days which will lead to major harvest issues.”

“We’re limited on the options in control for rice,” he said. “It’s not just a problem of row rice. We are also seeing them in flooded rice, all through the field. They are eating rice all the way down to the waterline.”

Lorenz said rice growers in California sought and received a Section 18 exemptions over the last three years. “We felt like that was our best option.”

Arkansas farmers who managed to replant after the floods and heavy rain in June have young, tender plants that are highly attractive to armyworms.

“Those crops are extremely susceptible to damage from armyworms,” Lorenz said.

What’s next

“My concern is that if we get another generation of them, the next wave could be unbelievable,” he said.

The first generation of armyworms matured into moths in Texas and Louisiana and flew northward. Now that they’re in Arkansas, “We’re making our own generation, which is what makes it so dangerous,” Lorenz said.

There’s also a chance that, depending on the environment, “the population could collapse,” he said. “There are some natural controls out there. When you get a big buildup a lot of things can happen. There are a lot of naturally occurring pathogens that can help control them.”

Some agents in southwest Arkansas found armyworms that had fallen victim to a naturally occurring virus. Lorenz is hoping that virus may provide another option for control in the future.

Arkansas is the nation’s leading rice producer. 

Use of product names does not imply endorsement.Source: University of Arkansas System Division of Agriculture, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.

Read Full Post »


ARS News ServiceFirefly on a green leaf

Photo by Maverick Dunavan, USDA-ARSSummer Lights
For media inquiries contact: Autumn Canaday, (202) 669-5480July 9, 2021

We often cherish the small memories of summer and all the joy that those memories bring. Maybe those memories are framed with ocean breezes, laughter, good food and time well-spent with friends or family. Whatever your summer memories include, I’d like to think that the yellow-green flash of the firefly is somewhere on the list.Did you spend the summer evenings of your youth capturing fireflies in a glass jar? Did you try to catch them in your hand? Did you ever wonder where these insects come from and why they are such a huge part of summer evenings? If so, this may be the perfect time to learn. First, it’s worth noting that despite their common name, these insects are not flies. They are actually a part of the Lampyridae beetle family, and they appear in late May or early June, often disappearing around September. But that varies according to species, region, and local weather conditions. Some species also emerge earlier than others. Like all beetles, fireflies have a complete metamorphosis, meaning they develop from eggs, to larvae, to pupae, to adults. Fireflies can spend up to two years as larvae, while their lifespan as adults only lasts a few weeks.Most people may find them flying around their yard, but fireflies prefer damp areas and you will often find them in meadows, woods, backyards or near sources of water. As they develop and grow, the larvae will eat other insect larvae, snails, and slugs. The adult diet is less well known, but research shows most adult fireflies don’t feed at all, and when they do, the diet can vary from species to species, but usually includes nectar, pollen, or other fireflies. During the day, nocturnal Lampyridae can be found resting on vegetation or tree trunks. Once evening falls, they begin mating behavior which results in the spectacular light show that we all know and love. During this time, the males will fly through the air and emit light from specialized organs on their abdomen to get the attention of the females. If the female is interested, she’ll reply with a flash of her own, attracting the male towards her. Each species has a specific flash pattern that differs in number, duration, and intervals between flashes. After mating the female lays her eggs and the adults soon die.Fireflies are actually considered a beneficial predator of garden pests, and sometimes, pollinators. Sometimes they are not quite hospitable to one another, as research shows that some female fireflies mimic the response of a different species to lure in a male firefly before eating him.  As everyone knows, fireflies won’t bite or sting you. So, it’s fine if they land on you while you enjoy a summer evening outdoors.There are now more than 136 species of fireflies in the United States and Canada, but they are currently in decline due to loss of habitat, pesticides, and light pollution. Be sure to enjoy their light show as they move about your backyard and be sure to set them free if they’ve been captured in a jar or your hand.We want them around for a long time.

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 agricultural research results in $17 of economic impact.
Interested in reading more about ARS research? Visit our news archiveU.S. DEPARTMENT OF AGRICULTURE
Agricultural Research Service

Read Full Post »

JULY 2, 2021

Phys.Org

How the potato blight pathogen penetrates the plant

by Wageningen University

Scientists discover how the potato blight pathogen penetrates the plant
Credit: Wageningen University

In the 19th century, the notorious pathogen Phytophthora infestans caused a large famine in Ireland and other parts of Western Europe. To this day, it continues to pose a major threat to global food production. It has long been a mystery how this microscopically small organism and other members of the Phytophthora genus mechanically gain entry through the protective layer on the leaves of crops. In a unique collaboration, Wageningen University & Research experts in plant pathology, cell biology and physics have now found an answer to this question. Their discovery also provides new leads to making the control of Phytophthora more effective, more efficient and more sustainable on the long term. Their findings are published in Nature Microbiology.

Plants are under constant threat from all kinds of pathogens. A number of these intruders bearing the difficult name Phytophthora (literally: plant destroyer), cause enormous damage yearly to all kinds of crops, such as potatoes, tomatoes, eggplant, cocoa, peppers, soy and date palm, as well as to woodlands and nature reserves. Phytophthora not only poses a major threat to our food security, but also results in vast economic damages, causing annual damage to the potato sector of approximately 6-7 billion euros.

Combatting Phytophthora is and remains problematic, in part because the pathogen and its target are engaged in an ongoing arms race. Tremendous resources are invested in the development of resistant crops through plant breeding, with the aim of becoming less dependent on chemical crop protection. There is also increasing interest in new forms of mixed cropping.

Utilising Insights from Mechanics

Another option has now arisen; preventing Phytophthora from gaining access to a plant altogether. Plants come equipped with a protective layer that serves to keep intruders like Phytophthora out. Yet, this microscopically small pathogen (smaller than one tenth of the thickness of a human hair) is able to penetrate this layer and initiate its disease process in plants. Despite decades of research, it remained unknown how they mechanically penetrate this layer. To solve this problem, WUR plant pathologists and cellular biologists joined forces with WUR physicists. The latter are specialists in mechanics, a branch of physics that studies how objects and materials move and respond under the action of forces acting upon them. Their combined knowledge, and new research tools developed in collaboration, could finally bring resolution to this puzzle.

“We discovered that Phytophthora uses clever tricks to sharpen its tubular infection structure to then cut through the surface of the plant with a sharp knife. Using this strategy, Phytophthora is able to infect its host, without brute force and with minimal consumption of energy. This is the first time that this mechanism has been uncovered, and really a fundamental discovery,” Joris Sprakel, professor in Physical Chemistry and Soft Matter, says.

More effective and sustainable protection

Phytopathology Professor Francine Govers sees plenty of leads to make the control of Phytophthora more effective, more efficient and more sustainable in the long run, without the usual suspects—chemicals and plant breeding—to circumvent the arms race. “The laws of mechanics tell us that Phytophthora is unable to penetrate the plant without first attaching itself tightly to the leaf surface.” To test this idea, as initial proof of feasibility, the research team sprayed the leaves of potato plants with a non-toxic and inexpensive substance that removes the leaf’s stickiness. This resulted in a reduction of around 65% in the level of infection. The effect even rose towards 100% in an optimized trial on artificial surfaces.

Apart from the fundamental breakthrough and investigating tools for combatting this kind of plant disease from a new perspective, the research also resulted in a new methodology; a kind of rapid testing method, that can reveal the effect and efficiency of pesticides in a rapid, accurate and inexpensive way. These novel tools could also make a significant contribution to the ongoing battle against plant diseases.

“Thanks to the engagement of Joris Sprakel and his team, including Ph.D. candidate Jochem Bronkhorst, we now know that there are a number of fundamental physical principles that could give a new twist to the arms race between pathogens and plants,” says Govers. “All in all, this research is a truly wonderful example of how collaboration across disciplinary borders can lead to breakthroughs.”


Explore further New resistance gene to devastating potato disease that caused Irish Famine


More information: Jochem Bronkhorst et al, A slicing mechanism facilitates host entry by plant-pathogenic Phytophthora, Nature Microbiology (2021). DOI: 10.1038/s41564-021-00919-7Journal information:Nature Microbiology

Read Full Post »

Fungus fights mites that harm honey bees

New fungus strain could provide a chemical-free method to help honey bees

ScienceDaily

Date:May 27, 2021Source:Washington State University

Summary: A new fungus strain bred in a lab could provide a chemical-free method for eradicating mites that kill honey bees. Varroa destructor mites play a large role in Colony Collapse Disorder, which destroys thousands of bee colonies every year. Share:

FULL STORY


A new fungus strain could provide a chemical-free method for eradicating mites that kill honey bees, according to a study published this month in Scientific Reports.

A team led by Washington State University entomologists bred a strain of Metarhizium, a common fungus found in soils around the world, to work as a control agent against varroa mites. Unlike other strains of Metarhizium, the one created by the WSU research team can survive in the warm environments common in honey bee hives, which typically have a temperature of around 35 Celsius (or 95 F).

“We’ve known that metarhizium could kill mites, but it was expensive and didn’t last long because the fungi died in the hive heat,” said Steve Sheppard, professor in WSU’s Department of Entomology and corresponding author on the paper. “Our team used directed evolution to develop a strain that survives at the higher temperatures. Plus, Jennifer took fungal spores from dead mites, selecting for virulence against varroa.”

Jennifer Han, a post-doctoral researcher at WSU, led the breeding program along with WSU assistant research professors Nicholas Naeger and Brandon Hopkins. Paul Stamets, co-owner and founder of Olympia-based business Fungi Perfecti, also contributed to the paper. Stamets is a fungi expert, well-known for using several species in applications ranging from medicine to biocontrol.

Varroa destructor mites, small parasites that live on honey bees and suck their “blood,” play a large role in Colony Collapse Disorder, which causes beekeepers to lose 30-50% of their hives each year. The mites feed on bees, weakening their immune systems and making them more susceptible to viruses.

The main tools beekeepers use to fight varroa are chemicals, such as miticides, but the tiny pests are starting to develop resistance to those treatments, Naeger said.

Metarhizium is like a mold, not a mushroom. When spores land on a varroa mite, they germinate, drill into the mite, and proliferate, killing it from the inside out. Bees have high immunity against the spores, making it a safe option for beekeepers.

Stamets, who did some of the initial testing with Metarhizium that showed the fungus couldn’t survive hive temperatures, was impressed by the work done by the WSU researchers.

“Science progresses through trial and error, and my technique wasn’t economical because of the hive heat,” he said. “But Jennifer did enormous amounts of culture work to break through that thermal barrier with this new strain. It’s difficult to really appreciate the Herculean effort it took to get this.”

Han and Naeger screened more than 27,000 mites for levels of infection to get the new strain.

“It was two solid years of work, plus some preliminary effort,” Han said. “We did real-world testing to make sure it would work in the field, not just in a lab.”

This is the second major finding to come from WSU’s research partnership with Stamets involving bees and fungi. The first involved using mycelium extract that reduced virus levels in honey bees.

“It’s providing a real one-two punch, using two different fungi to help bees fight varroa,” Stamets said. “The extracts help bee immune systems reduce virus counts while the Metarhizium is a potentially great mite biocontrol agent.”

The next step is to seek approval from the Environmental Protection Agency to use Metarhizium on hives used in agriculture. The team must also finalize delivery methods for beekeepers to apply the fungus in hives.

“We hope in 10 years that, rather than chemical miticides, Metarhizium is widely used to control Varroa mites,” Sheppard said. “And that the mite problem for beekeepers has been significantly reduced.”

The team thinks the methods they developed to evolve Metarhizium for varroa control could be used to improve biocontrol agents in other crop systems as well.

The majority of the funding for this work came from private donations from individuals and foundations. Additional funding came from Washington State Department of Agriculture (WSDA) Specialty Crop Block Grant K2531 and the USDA National Institute of Food and Agriculture, Hatch 1007314.


Story Source:

Materials provided by Washington State University. Original written by Scott Weybright. Note: Content may be edited for style and length.


Journal Reference:

  1. Jennifer O. Han, Nicholas L. Naeger, Brandon K. Hopkins, David Sumerlin, Paul E. Stamets, Lori M. Carris, Walter S. Sheppard. Directed evolution of Metarhizium fungus improves its biocontrol efficacy against Varroa mites in honey bee coloniesScientific Reports, 2021; 11 (1) DOI: 10.1038/s41598-021-89811-2

Read Full Post »

Why demand is expected to be strong for virus-resistant wheat

Wheat with the Bdv2 gene (left) and a non-Bdv2 crop © RAGTWheat with the Bdv2 gene (left) and a non-Bdv2 crop © RAGTf

Farmer’s Weekly

Insecticide-free wheat has moved a step closer with the arrival of the hard Group 4 winter wheat variety Wolverine, which is the first to offer barley yellow dwarf virus (BYDV) resistance.

Added to the latest AHDB Recommended List on a yield of 102%, Wolverine has a specific recommendation for resistance to BYDV and sets an exciting tone for future wheat variety introductions from breeder RAGT, many of which will have resistance to both BYDV and orange wheat blossom midge.

While Wolverine is a high-yielding feed variety, the company also has bread-making wheats with both types of resistance in development – many of which should eliminate the need to apply insecticides throughout the entire growing season.

Against a background of the loss of insecticidal seed treatments, rising resistance levels in pests to the remaining foliar sprays and greater scrutiny of pesticide use, the development of these varieties is a breakthrough.

Their arrival is expected to be as well-received by the supply chain as it is by farmers, in the industry’s quest to sharpen its environmental credentials.

Seed demand

After a limited seed release last year ahead of the recommendation decision, there is enough seed of Wolverine available to meet demand for this autumn’s wheat plantings, RAGT managing director Lee Bennett confirms.

He believes the variety could take a significant market share.Lee Bennett in a trial plot

Lee Bennett © RAGT

“The ideal situation is to have this BYDV resistance in a variety that suits early drilling,” he says. “That’s exactly what we have in Wolverine.”

After two consecutive wet autumns and difficulties with wheat drilling schedules, the opportunity for farmers to get under way while conditions are good, without putting the crop at unnecessary risk from virus-carrying aphids, is a bonus, he notes.

“This will be the second year without the Deter (clothianidin) seed treatments that gave such cost-effective control. The approval of Wolverine gives them a different, more environmentally friendly solution.”

Genetic solution

The genetic alternative to chemical control is performing well in the field, says his colleague Tom Dummett, who confirms that the Bdv2 gene used in Wolverine brings season-long protection from the aphids that transmit the virus.

Explore moreKnow How

Visit our Know How centre for practical farming advice

“The aphids still arrive, but Wolverine doesn’t express any virus symptoms and the virus doesn’t multiplicate in the plant,” he explains.

“We’re very happy with the way that the gene is working. It’s proved effective in Australia for almost 20 years and is now in the right genetic background to work well in the UK.”

Having previously conducted trials to look at the value of the resistance at different sowing dates and whether the use of one insecticide spray could protect the gene or give a yield uplift, this year’s work by RAGT has a different focus.

The plots were all drilled in early September and then inoculated with aphids infected with the PAV strain of BYDV, both in the autumn and the spring.

BYDV pressure

The idea was to create severe BYDV pressure, explains Mr Dummett, with one-third being left untreated, one-third receiving an autumn insecticide, and the remaining plots getting both an autumn and spring insecticide.

At the time of Farmers Weekly‘s visit in June, varieties without the BYDV resistance gene were showing clear symptoms of the virus in the untreated plots.

Wolverine and the other RAGT lines with the Bdv2 gene were symptom-free.

The PAV strain of BYDV is the most common, Mr Dummett says, but the company is confident that the resistance is broad-spectrum as tests have confirmed that it also controls the MAV and RPV strains.

Wolverine’s agronomic features

Agronomically, Wolverine is a later-maturing type, with a +2 for ripening.

It has stiff straw and good resistance to brown rust, but is middle-of-the-road for septoria (5.3) and did take on some yellow rust last year, so has a score of 5. As such, it needs to be grown with care and frequent monitoring.

Seed cost

The previous cost of using Deter (clothianidin) seed treatments and an insecticide for BYDV control has been factored into the cost of growing Wolverine.

As it was last year, the variety will be sold via the Breeders’ Intellectual Property Office system, which means that the value of the trait will be charged direct to farmers on an area basis rather than by tonnage.

That charge will be £33/ha, and RAGT points out that it covers season-long protection and eliminates the need to monitor aphid populations or repeatedly spray at a busy time of year.

Competitive advantage

RAGT has a head start over other breeding companies when it comes to BYDV resistance, as it is the only UK plant breeder with Bdv2.

The company has two feed wheat varieties coming along closely behind Wolverine, followed by four bread-making types with both BYDV and orange wheat blossom midge resistance.

The Bdv2 gene originated in goat grass and was translocated onto a wheat chromosome by Australian researchers, who went on to breed BYDV-resistant wheats.

There are four other known BYDV resistance genes, most of which are being investigated by RAGT. Bdv3 and Bdv4 work differently to Bdv2, for example, but may bring other benefits when put into the right genetic background.

Read Full Post »

Misconceptions about biological controls

June 24, 202188

By Ethan Proud
PREVIEW Columnist

For some, biological controls (biocontrols) seem like a silver bullet, capable of removing invasive species without using herbicides. To others, it seems counterintuitive to release a non-native species on an invasive species wreaking havoc on the ecosystem.

Biocontrols, unfortunately, do not eradicate a population, though there are some exceptions and populations can decrease by large margins when an insect herbivore is released into the environment. These biocontrol agents will suppress the population of invasive species and can help slow the spread, though they will not completely eradicate the noxious weed. 

Biocontrols must be released repeatedly to see success and a onetime release will not yield great results. Paired with chemical or mechanical control, an acceptable level of control can be achieved. Release biocontrols in areas that are difficult to reach with a backpack, ATV mounted sprayer or equipment for manual control. It’s easier to hike into a difficult area with a small container of insects than it is to carry a shovel and a bag — especially when the bag is completely full and it is time to hike out. Utilize mechanical and chemical control around the perimeter of the release site and you will have a one-two punch, biocontrols suppressing the heart of the infestation and chemical or mechanical control containing the spread.

When it comes to approving a new biocontrol agent, the insects must first be carefully studied through a round of choice and no-choice tests, where it is determined that A) the insect will feed on only the target species and B) the insect will starve to death before finding a new food source. These tests are conducted by the U.S. Department of Agriculture Animal and Plant Health Inspection Service Plant Protection and Quarantine Program, or USDA APHIS PPQ for short. The process of approval takes many years, meaning that new biocontrol agents are not only very exciting, but few and far between.

In short, biocontrol agents need to be paired with another control method to be truly effective and they are not an option for certain weeds. However, they are a great tool for integrated pest management and can reduce our dependency on herbicides.

For more information on biological control agents that can be released in Colorado and are available to landowners, visit the Colorado Department of Agriculture website and click Biocontrols underneath the Conservation Banner.

Archuleta County Weed and Pest is your local resource for managing noxious weed populations and controlling other pests.

Read Full Post »

Click Here for Japanese Translation

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

昆虫ファームが無農薬トマトを後押し フランス

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

AFP-JIJI PRESS NEWS JOURNAL

Read Full Post »

Mushroom growing out of fossilized ant reveals new genus and species of fungal parasite

IMAGE
IMAGE: Oregon State University research has identified the oldest known specimen of a fungus parasitizing an ant, and the fossil also represents a new fungal genus and species. A mushroom is…
view more Credit: George Poinar Jr., OSU

CORVALLIS, Ore. – Oregon State University research has identified the oldest known specimen of a fungus parasitizing an ant, and the fossil also represents a new fungal genus and species.

“It’s a mushroom growing out of a carpenter ant,” said OSU’s George Poinar Jr., an international expert in using plant and animal life forms preserved in amber to learn about the biology and ecology of the distant past.

A mushroom is the reproductive structure of many fungi, including the ones you find growing in your yard, and Poinar and a collaborator in France named their discovery Allocordyceps baltica. They found the new type of Ascomycota fungi in an ant preserved in 50-million-year-old amber from Europe’s Baltic region.

“Ants are hosts to a number of intriguing parasites, some of which modify the insects’ behavior to benefit the parasites’ development and dispersion,” said Poinar, who has a courtesy appointment in the OSU College of Science. “Ants of the tribe Camponotini, commonly known as carpenter ants, seem especially susceptible to fungal pathogens of the genus Ophiocordyceps, including one species that compels infected ants to bite into various erect plant parts just before they die.”

Doing so, he explains, puts the ants in a favorable position for allowing fungal spores to be released from cup-shaped ascomata – the fungi’s fruiting body -protruding from the ants’ head and neck. Carpenter ants usually make their nests in trees, rotting logs and stumps.

The new fungal genus and species shares certain features with Ophiocordyceps but also displays several developmental stages not previously reported, Poinar said. To name the genus, placed in the order Hypocreales, Poinar and fellow researcher Yves-Marie Maltier combined the Greek word for new – alloios – with the name of known genus Cordyceps.

“We can see a large, orange, cup-shaped ascoma with developing perithecia – flask-shaped structures that let the spores out – emerging from rectum of the ant,” Poinar said. “The vegetative part of the fungus is coming out of the abdomen and the base of the neck. We see freestanding fungal bodies also bearing what look like perithecia, and in addition we see what look like the sacs where spores develop. All of the stages, those attached to the ant and the freestanding ones, are of the same species.”

The fungus could not be placed in the known ant-infecting genus Ophiocordyceps because ascomata in those species usually come out the neck or head of an ant, Poinar said, and not the rectum.

“There is no doubt that Allocordyceps represents a fungal infection of a Camponotus ant,” he said. “This is the first fossil record of a member of the Hypocreales order emerging from the body of an ant. And as the earliest fossil record of fungal parasitism of ants, it can be used in future studies as a reference point regarding the origin of the fungus-ant association.”

###

Findings were published in Fungal Biology.

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

Read Full Post »

Unusual prey: Spiders eating snakes

There are spiders that eat snakes; observations of snake-eating spiders have been reported around the world. Two researchers from Basel and the US consolidated and analyzed over 300 reports of this unusual predation strategy

28-Jun-2021 1:35 PM EDT, by University of Baselfavorite_border

Newswise: Unusual prey: Spiders eating snakes

Daniel R. Crook

Juvenile scarlet snake (Cemophora coccinea, Colubridae) entrapped on web of Latrodectus geometricus, observed in a private residence in Georgia, USA.

Newswise — There are spiders that eat snakes. Observations of snake-eating spiders have been reported around the world. Two researchers from Basel and the US consolidated and analyzed over 300 reports of this unusual predation strategy.

Spiders are primarily insectivores, but they occasionally expand their menu by catching and eating small snakes. Dr. Martin Nyffeler, arachnologist at the University of Basel, and American herpetologist Professor Whitfield Gibbons of the University of Georgia, USA, got to the bottom of this phenomenon in a meta-analysis. Their findings from a study of 319 occurrences of this unusual feeding behavior recently appeared in the American Journal of Arachnology.

It turns out that spiders eat snakes on every continent except Antarctica. Eighty percent of the incidents studied were observed in the US and Australia. In Europe, on the other hand, this spider feeding behavior has been observed extremely rarely (less than 1 percent of all reported incidents) and is limited to the consumption of tiny, non-venomous snakes of the blind snake family (Typhlopidae) by small web-building spiders.

Black widows are particularly successful

Incidents of snake predation by spiders have never been reported from Switzerland. A possible explanation is that Switzerland’s native colubrids and vipers are too big and heavy even when freshly hatched for Swiss spiders to subdue them.

The data analysis also showed that spiders from 11 different families are able to catch and eat snakes. “That so many different groups of spiders sometimes eat snakes is a completely novel finding,” Nyffeler emphasizes.

Black widows of the family Theridiidae were the successful snake hunters in about half of all observed incidents. Their potent venom contains a toxin that specifically targets vertebrate nervous systems. These spiders build webs composed of extremely tough silk, allowing them to capture larger prey animals like lizards, frogs, mice, birds and snakes.

Big catch

Another new finding from the meta-analysis: spiders can subdue snakes from seven different families. They can outfight snakes 10 to 30 times their size.

The largest snakes caught by spiders are up to one meter in length, the smallest only about six centimeters. According to the statistical analysis done by the two researchers, the average length of captured snakes was 26 centimeters. Most of the snakes caught were very young, freshly hatched animals. That some spiders are able to subdue oversized prey is attributable to their highly potent neurotoxins and strong, tough webs.

Possible insights into the effect of spider venom

Many spider species that occasionally kill and eat snakes have venom that can also be lethal to humans. That means the venom of various spider species has a similar effect on the nervous systems of snakes and humans. For this reason, observations of vertebrate-eating spiders can also be important for neurobiology, as they allow conclusions to be drawn about the mechanisms by which spider neurotoxins affect vertebrate nervous systems.

“While the effect of black widow venom on snake nervous systems is already well researched, this kind of knowledge is largely lacking for other groups of spiders. A great deal more research is therefore needed to find out what components of venoms that specifically target vertebrate nervous systems are responsible for allowing spiders to paralyze and kill much larger snakes with a venomous bite,” says Martin Nyffeler.

The captured snakes are anything but helpless themselves: about 30 percent are venomous. In the US and South America, spiders sometimes kill highly venomous rattlesnakes and coral snakes. In Australia, brown snakes (which belong to the same family as cobras) often fall prey to redback spiders (Australian black widows). Martin Nyffeler says, “These brown snakes are among the most venomous snakes in the world and it’s really fascinating to see that they lose fights with spiders.”

Additional information

Storage of energy reserves

When a spider catches a snake, it will often spend hours or days feasting on such a large prey. Spiders have an irregular feeding pattern. When a lot of food is available, they eat in excess, only to go hungry for long periods again afterward. They store excess food as energy reserves in their body and use it to tide them over longer periods of starvation.

Still, a spider often eats only a small part of a dead snake. Scavengers (ants, wasps, flies, molds) consume what remains.

###

SEE ORIGINAL STUDYREQUEST AN EXPERT

MEDIA CONTACT

REGISTER FOR REPORTER ACCESS TO CONTACT DETAILS

CITATIONS

American Journal of Arachnology

TYPE OF ARTICLE

Research Results

SECTION

SCIENCE

CHANNELS

Environmental ScienceNatureWildlifeStaff PicksAll Journal News

KEYWORDS

SpiderSnakeSpider venomPrintFacebookTwitterLinkedInEmail

Read Full Post »

The company is working hard so that the product is available in 2022

Koppert is developing a biological solution against “Nezara viridula”

Over the last decade, the green bug (Nezara viridula) has plagued pepper, aubergine, and cucumber greenhouses in southern Europe and its presence is growing in state-of-the-art and heated greenhouses in the north, east, and central parts of Europe. The elimination of chemicals in combination with climate change has increased the pressure of this pest in greenhouses.


The green bug (Nezara viridula) on a pepper plant.

The fight against the green bug is a great challenge, and to date, it can only be done with chemical products. However, these products affect the population of the natural enemies of thrips, spider mites, aphids, and whiteflies that keep these pests under control. There is the possibility of manually removing the green bug from the crop, but this is only feasible if the pressure of the pest in the crop is low; therefore this technique has had little success.

The Nezara problem was identified early by Koppert. In 2018 the company began research with this pest’s most effective natural enemy: a wasp that parasitizes its eggs. The first field trials are promising and show that Nezara can be fought well in practice. Large-scale trials in different countries are expected to confirm these results later this year.

“The damage caused by Nezara is enormous and often leads to early removal of crops. The fight against this pest is complicated, and the only remedy is to use chemicals. That’s why we are pleased that we’re close to being able to provide a natural solution to our customers. Our international team is dedicated body and soul to offering a suitable solution against Nezara as soon as possible,” stated Bart Sels, Head of Koppert Belgium.

For more information:

Koppert 
C/ Cobre 22
Pol. Industrial Ciudad del Transporte del Poniente
04745 La Mojonera, Almería (España)
Tel.: +34 950 554 464
Fax: +34 950 553 905
www.koppert.es

Publication date: Mon 28 Jun 2021

Read Full Post »

Older Posts »