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BCPC’s GM/Biotech Crops Report – April 2022

5th April 2022

  • GM/Biotech Crops Monthly Reports (BELOW) form part of BCPC’s free three-tier Biotech Crops Info service.
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GM/Biotech Crops Monthly Report April 2022

Lettuce in space

Astronauts that spend a long time in space can suffer from a loss of bone density due to the reduced gravity but now a team at the University of California have developed a genetically-modified lettuce that produces a drug that can offset this loss and that can be grown in space to provide the astronauts with fresh green leaves to eat. Pic: Mel Edwards. Full Story.

Antibiotics on crops

While Europe bans neonicotinoids to ensure no harmful effects to bees, America is spraying apple and pear orchards with streptomycin to control the bacterial disease fire blight. A study has shown that bees exposed to the streptomycin are less active and collect less pollen than those that are not exposed to the antibiotic.
Full Story.

An elixir of youth

Some people try blood transfusions from young people to recapture that youthful zest for life and now a study has produced some evidence supporting that hope. Young mice blood contains packets of chemicals (extracellular vesicles) budded off from dividing cells that, when injected in to old mice, restores grip strength, stamina and motor coordination. Sadly the effect wears off after a couple of months but another injection can restore it.
Full story

BT maize resistant to stem borer attack

An evaluation of BT maize in Uganda has confirmed a reduction of leaf damage and stem attack that has led to yield increases of 30 – 80%.
Full Story.

Salt-tolerant cotton

A relative of Arabidopsis has yielded a trait that can be used to confer salt tolerance to cotton which could allow the crop to be grown on more land but could also boost yields in areas where it is already grown.
Full Story

Herbicide-tolerant tomatoes

Scientists in Korea have used gene editing to alter three enzymes in tomatoes. The benefits of changes to PDS and EPSPS enzymes are unclear but the changes to the ALS enzyme can confer tolerance of ALS herbicides similar to the naturally-occurring tolerance recently introduced in sugar beet.
Full Story

Potato genome decoded

Scientists at the Max Planck Institute and the Ludwig Maximillian University have decoded the entire genome of potatoes and this knowledge is to be used to develop improved varieties for future cropping. The following link takes you to the German text which can be translated by computer.
Full Story

Gene expression imbalance boosts wheat yields

Researchers at Kansas University have found that varying the expression of various genes in wheat can affect the grain size and final yields. This knowledge can possibly be used to optimise yields of new varieties.
Full Story

Control of Fall Army Worm

Pilot studies in Brazil have shown that release of Oxitec’s ‘Friendly’ male army worms can reduce the populations of army worms due to the males carrying a male only trait and that this reduction will help to protect the Bt maize that is grown there from resistance developing in the wild population. It is very target specific and has no effect on other species such as bees.
Full Story

USDA approved gene-edited cattle

The USDA has decided that gene-edited beef cattle that have shorter hair than unedited cattle pose no safety concerns and can be marketed without waiting for a specific approval:
Full Story

Europe approves transgenic maize with stacked traits

The EFSA finds no safety concerns in GM maize with stacked traits for insect resistance and tolerance of glyphosate and glufosinate. This permits the import of these crops but it still does not allow them to be grown in Europe.
Full Story

Stripe rust resistance in wheat

An international team has identified the specific gene that confers resistance to stripe rust in the African bread wheat variety ‘Kariega’ and now this trait can be transferred to other varieties.
Full Story

Gene-silencing for weed control

Colorado University has developed a spray that contains antisense oligonucleotides that penetrate the leaves of the weed Palmer amaranth and silence essential genes in the weed. Palmer amaranth has developed resistance to a number of herbicides but this spray is specific to this weed and has no effect on the crop or non-target organisms.
Full Story

Nutritional Impact of regenerative farming

The University of Washington has compared crops grown on land under regenerative farming management with crops grown on adjacent conventionally farmed land and has shown that the regenerative farming crops have higher levels of vitamins, minerals and other phytochemicals. They don’t give any comparison of the yields achieved though and perhaps the higher levels of vitamins etc are simply due to them being distributed through lower yielding crops.
Full Story

Transgenic sugarcane

Sugarcane with overexpressed sucrose-phosphate synthase has been trialled in Indonesia has shown increased tiller number, height and yield than conventional varieties without affecting bacterial diversity or gene horizontal flow in the soil.
Full Story

Potato virus Y resistance

Researchers in Iran have used gene-silencing techniques to develop potatoes that exhibit resistance to potato Y virus.
Full Story

GM barley trials in the UK

Fertiliser prices have gone through the roof and NIAB in conjunction with Cambridge University at the Crop Science Centre are to trial gene modified and gene edited lines of barley to see if they can improve the nitrogen and phosphorus uptake of the plants and make them less reliant on applied fertilisers. If successful on barley, it could be rolled out to other crops.
Full Story

Palm oil replacement

Palm oil is widely used in many products but the proliferation of palm plantations is responsible for a lot of habitat loss throughout the world. Now a team at Nanyang technological University in Singapore have developed a technique for producing the oil from common microalgae.
Full Story

Corn borer resistant maize

Zhejiang University in China has developed a genetically modified maize that has insect resistant traits and a 5 year study has shown it can give up to 96% reduction in corn borer damage and a 6 – 10% yield increase over conventional varieties.
Full Story

THE LATEST ADDITIONS TO THE  GM/BIOTECH DATABASE ARE:

The latest approvals of biotech crops to report this month:

• GMB151 – soybean tolerant of isoxaflutole herbicide approved for food use in Canada and for environmental use in America

FOR INSTANT ACCESS TO GM BIOTECH MANUAL CLICK HERE (Registration required)

Already Registered? Click here to access

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Technology to address pest infestation in cowpea as Ghana progresses in GMOs

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Ghana is progressing steadily with the introduction of Genetically Modified Cowpea. Known locally as beans, scientists at the Agricultural Research Institute at Nyankpala in the Savannah Region, have completed work on a technology to address the huge pest infestation of the crop.

A dossier to that effect has been gazetted by the National Biosafety Authority. The document contains a request by the Researchers to environmentally release and market the beans. Joyce Gyekye reports that scientists at the Savannah Agricultural Research Institute, SARI of the CSIR have been conducting trials for the introduction of a gene into the black-eye beans that is mostly destroyed by a pest called Maruca.

To reduce the pest infestation, farmers spray the plant about eight times before harvesting. This comes with a cost to them as well as health and environmental issues.

Realising this, Ghana, Nigeria, and Burkina Faso agreed to an introduction of a gene that stops about 80% of the destruction of the beans. The decade journey by the researchers has been completed and the dossier gazetted by the National Biosafety Authority; a body set up to regulate the safe use, handling, and transportation of GMOs in Ghana.

Dr. Jerry Nboyine is the Principal Investigator of GM Cowpea. He expressed optimism about the project. He also said there had been subsequent laboratory works by participating countries.

He clears the misconception about seed control by multinational biotech companies spread by anti-GM groups.

The Chief Executive Officer of the NBA, Eric Okoree, says the notice of dossier is for the relevant comments from the public within 60 days.

Nigeria released its GM Cowpea on the market about two years ago.

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Silencing horizontally transferred genes for the control of the whitefly Bemisia tabaci

Intracellular symbiosis impacts many aspects of insect biology, and disruption of these symbioses is a novel insect-pest-control strategy. Horizontally transferred genes (HTGs) are critical for insect-intracellular symbiont association, representing candidate molecular targets for symbiosis disruption.

However, few studies have tested this in the laboratory and under field conditions. Biotin and lysine HTGs are involved in Bemisia tabaci MEAM1 symbiosis persistence. In this study, we showed that whitefly biotin and lysine genes can be silenced by the tobacco rattle virus (TRV), a tobravirus. Then, we demonstrated that the vector 2mDNA1, an engineered begomovirus transmitted by B. tabaci, was effective for silencing B. tabaci MED HTGs in the laboratory. The 2mDNA1-silencing biotin HTGs reduced levels of biotin, as well as survival, fecundity, and population increases of whiteflies. The 2mDNA1-silencing biotin HTGs did not impact the titers of symbionts in F0 whiteflies but decreased the titers of symbiont Portiera in F2 whiteflies. The 2mDNA1-silencing lysine HTG reduced levels of lysine, titers of Portiera in both F0 and F2 whiteflies as well as the survival, fecundity, and population increases of whiteflies.

The 2mDNA1-mediated silencing of whitefly genes is horizontally transmitted among whiteflies, enhancing the effectiveness of gene silencing. We further revealed that the vector 2mDNA1 can be used to silence whitefly HTGs and inhibit whitefly performance in the greenhouse. This study demonstrates that repressing the expression of insect HTGs through a modified virus is feasible for the control of phloem-feeding insect pests.

Read the complete research at www.researchgate.net.

Wang, Tian-Yu & Luan, Jun-Bo. (2022). Silencing horizontally transferred genes for the control of the whitefly Bemisia tabaci. Journal of Pest Science. 10.1007/s10340-022-01492-6. 

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Missouri ag department scouts for emerging grape pest

Lana2011/Getty Images; Lawrence Barringer, Bugwood.orginset of spotted lanternfly on photo of grapes

WINE INDUSTRY CONCERN: Missouri’s grape growers should be on the watch for the spotted lanternfly, which was detected in a neighboring state last year. It can decimate vineyards. The Missouri Department of Agriculture continues to scout for this invasive insect.

With spotted lanternfly found in the heartland, state officials are ramping up reporting efforts to protect wine industry.

Mindy Ward | Mar 23, 2022

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Farm Progress Show

Aug 30, 2022 to Sep 01, 2022

At the end of 2021, a Kansas 4-H member turned in his bug collection project. There, pinned to the Styrofoam board, was an invasive insect only thought to be along the East Coast — the spotted lanternfly.

The young man found the spotted lanternfly — a unique spotted bug that feeds on grapevines and fruit trees — in his backyard. First detected in Pennsylvania in 2014, it sucks out the nutrients in the plants causing them to die.

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“They did not find any large population of spotted lanternfly in Kansas, but that doesn’t mean it’s not there,” says entomologist Kevin Rice with University of Missouri Extension. “You’re looking for a needle in a haystack really.”

But he adds it is pest everyone needs to look for to protect the state’s wine industry.

Missouri is home to more than 1,700 acres of grapes, with more than 400 vineyards. There are 127 wineries producing more than 937,850 gallons of wine. This industry alone adds $3.2 billion to the state’s economy. According to Missouri Partnership data, the state welcomes 875,000 wine-related tourists each year, resulting in 1.16 million gallons of wine sold annually.

“We’re very concerned for our vineyards, and those that might have grapevines in their backyard as hobby crops,” says Sarah Phipps, Missouri Department of Agriculture plant protection specialist. She recently sat in on a Spotted Lanternfly Summit hosted by the Pennsylvania Department of Agriculture and heard from an affected vineyard owner.

A grape grower’s experience

Phipps says the owner had two vineyards, one at ground zero, about 2 miles away from where they found the initial infestation of spotted lanternfly in Pennsylvania in 2014. By 2017, his vineyard was overrun by the insect. “His vineyard was unfortunately gone,” she says.

Once this invasive insect appears in a vineyard, it is difficult and costly to eradicate. The same vineyard owner had a second location where spotted lanternfly showed up in 2017. Two years later, it too required chemical control options.

Fortunately, Phipps says research over the last seven years provides some management options; however, they are expensive.

In 2016, growers reported using 4.2 pesticide applications to rid vineyards of spotted lanternfly, but by 2018, it had increased to 14 pesticide applications just to keep the insect in check. “So that was a $54.63-an-acre cost in 2016 to a $147.85-an-acre in 2018. That’s a pretty significant increase of dollars spent,” Phipps adds.

Worse, patrons at wineries in the impacted states had to deal with the fly. The insect was on tables, in wine glasses and individuals’ hair. Many owners reported placing fly swatters at tables to help kill the spotted lanternfly. The impact to the wine industry’s tourism is also a concern.

Stories like these strengthen Phipps and the Missouri Department of Agriculture’s drive to protect the wine industry by taking a proactive approach to this pest.

Scouting for spotted lanternfly

“We have surveyed a little over 30 counties,” Phipps says. “We have surveyors located across the state and have asked them to take some time and survey tree of heaven to see if there is any spotted lanternfly on those plants.”

Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.orgspotted lanternfly feeding on tree of heaven

The spotted lanternfly feeds on tree of heaven, which can be found on Missouri’s roadways and railroad tracks. It also has been known to appear in urban settings around commercial buildings, which is concerning since the female can lay eggs on metal making it easy to transport across the state.

According to Phipps, the tree of heaven is a food source for the spotted lanternfly. This invasive tree species can be found growing alongside roadways, railroad tracks or industrial buildings. Phipps also warns that the spotted lanternfly females lay their eggs on rail cars and trucks, increasing the potential for the insect to spread rapidly throughout the entire U.S. Already in Pennsylvania, trucks must be inspected and certified that they are not carrying spotted lanternfly.

The Missouri Department of Agriculture is working with USDA surveyors to combine data sets to create a yearly account for the movement, if any, of the insect. The state is also looking for any individual, landowner or farmer to help in identifying and reporting spotted lanternfly.

map of Missouri counties surveyed for spotted lanternflies on tree of heaven plants

Identifying the enemy

The spotted lanternfly is an invasive planthopper, similar to a large aphid, with a straw-like mouth that sucks the sap out of plants. The adult is about 1 inch long and a half-inch wide with its wings expanded.

It resembles a moth but has distinct markings. The forewing is gray with black spots, and the wing tips are reticulated black blocks outlined in gray, according to Rice. The back wings have distinct patches of red and black with a white band.

The legs and head are black; the abdomen is yellow with broad black bands. The insects during their immature stages are black with white spots, and develop red patches as they grow.

life cycle of spotted lanternfly graphic

“We don’t have a whole lot of native insects that really look like this,” Rice says. “So if you see this, we ask that you call the Department of Ag and report it.”

Rice stresses that spotted lanternfly is not creating economic damage in field crops now; however, Pennsylvania reported it in soybean fields in 2017. “It’s not going to affect corn or soybeans, but it does have such an impact on the vineyards that we want to report it,” Rice says. “So if you see it, we ask that you call the Missouri Department of Agriculture and report it.”

Rice says it is important to eradicate a small population rather than let it go unchecked and grow into a larger problem for the state’s ag industry.

Have you seen this invader? Spotted lanternfly graphic

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Field cage study highlights safety of classic biological control agent against devastating invasive fruit fly

by CABI

Field cage study highlights safety of classic biological control agent against devastating invasive fruit fly
Drosophila suzukii on cherry. Credit: Tim Haye, CABI

CABI scientists have led new research which highlights the safety of a classical biological control agent against the devastating invasive fruit fly Drosophila suzukii which attacks over 150 wild and cultivated fruits, including cherries, blueberries and strawberries, as well as the fruits of ornamental plants.

Drosophila suzukii, or commonly called Spotted Wing Drosophila, is a frugivorous insect native to Eastern Asia that was accidentally introduced to the Americas and Europe in the 2000s, where it rapidly spread. Unlike sympatric Drosophila species in invaded areas, D. suzukii females are able to lay eggs inside unwounded ripening fruits due to their specialized egg-laying organ that is equipped with saw teeth, providing it with a unique niche virtually free from competition.

The resulting high abundance of D. suzukii is leading to extensive damage, making it a major problem for fruit growers, especially in the soft fruit industry.

Field cage releases of the parasitoid G1 Ganaspis cf. brasiliensis carried out in two regions of Switzerland in August 2021 supports findings from previously conducted laboratory-based experiments and the low risk for non-target effects on native Drosophila spp.

The study, carried out with colleagues from the Repubblica e Cantone Ticino, Agroscope, and the Institute of Agricultural Sciences (IAS) of ETH Zurich, and—all in Switzerland, revealed that larvae of the target species D. suzukii feeding in fresh fruits was readily parasitized and of 957 emerging parasitoids, only one was from larvae of the non-target species D. melanogaster feeding on decomposing fruits.

Lead researcher Dr. Lukas Seehausen, based at CABI in Switzerland, said, “Released parasitoids had the choice to parasitize either D. suzukii larvae in fresh fruits, blueberries or elderberries, or the non-target native species D. melanogaster in decomposing fruits, which is their natural habitat.

“The results were unequivocal in that parasitism of D. suzukii larvae feeding in fresh fruits was on average 15%, whereas only one parasitoid emerged from D. melanogaster feeding on decomposing fruits, which is a mere 0.02% parasitism.

“The results achieved under semi-field conditions supports findings from previous laboratory experiments that the parasitoid G1 G. cf. brasiliensis is highly specific to D. suzukii larvae feeding in fresh fruits and parasitism of the closely related D. melanogaster naturally feeding on decomposing fruits is very rare.

“Because in its invaded range, D. suzukii is the only Drosophila species that can attack and develop in undamaged fresh fruits, we conclude that possible non-target impacts are a low and acceptable risk for the control of the destructive invasive spotted wing drosophila.”

In their conclusion, the scientists note that with the first releases of G. cf. brasiliensis in Italy in 2021, a recent acceptance of the application for releases of the same parasitoid in the US, and the submission of an application in Switzerland in February 2022, the research starts to be implemented into practice.

The research was published in Journal of Pest Science.


Explore further

Natural enemy of Asian fruit fly, previously thought to be one species, is in fact two


More information: M. Lukas Seehausen et al, Large-arena field cage releases of a candidate classical biological control agent for spotted wing drosophila suggest low risk to non-target species, Journal of Pest Science (2022). DOI: 10.1007/s10340-022-01487-3

Provided by CABI

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The Case of the Onion Thrips: An IPM Mystery

If your thrips biocontrol program isn’t working, it may be because your thrips have changed.

February 28, 2022


By Ashley Summerfield, Dr. Sarah Jandricic, Dr. Rose Buitenhuis & Dr. Cynthia Scott-Dupree

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This budding chrysanthemum plant is damaged by onion thrips. Photo credit: A. Summerfield

Thrips were already the most formidable pest tormenting greenhouse ornamental growers in Canada to begin with, but if you’ve noticed that they are even harder to control than they used to be, you’re not alone.

Over the past few years, growers started seeing more thrips outbreaks, and their biocontrol programs weren’t always keeping up. That’s when Dr. Sarah Jandricic of OMAFRA discovered we might have a mystery thrips on our hands.

It turns out there was a new villain on the scene: onion thrips (Thrips tabaci). They make up on average around one quarter of the thrips found in floriculture greenhouses in the Niagara region of Ontario, but may account for more than half depending on the year, crop, or location.

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With the culprit identified, an investigation began (in the form of a Master’s thesis) to learn more about our new foe and, most importantly, how to stop it.

Criminal Record: a brief history of thrips in Canadian greenhouses

Western flower thrips (WFT; Frankliniella occidentalis) have been the primary pest thrips in greenhouse ornamentals since they found their way from the southwest coast of the US to the rest of North America and the world in the 1980s-1990s.

Onion thrips (OT) on the other hand, have been here for much longer. They were first described in North America 140 years ago. Before widespread synthetic pesticide use, OT were a common pest in greenhouses, but are now mostly associated with outdoor crops, and onions in particular.

In the 1990s, changes to pesticide spray practices in onion crops for controlling onion maggot  in Ontario inadvertently led to increased OT pressure in this crop.1 Around the same time, greenhouse growers were moving away from calendar sprays of pesticides and adopting more IPM tactics (e.g. monitoring-based spraying, forays into biocontrol) in response to increasingly pesticide-resistant WFT populations.

This combination of increased OT populations outside and the almost complete adoption of biological control for greenhouse pests by 20182 likely led to OT resuming its criminal activity in greenhouses. With fewer pesticides incidentally controlling this less pesticide-resistant thrips species, we now have a classic case of pest resurgence on our hands.

Breaking & Entering

Thrips enter your greenhouse in one of two ways: you either bring them in on imported plant material, or they come in from the outside on their own.

Past research at Vineland Research and Innovation Centre demonstrated just how many thrips you could be bringing in on cuttings like chrysanthemums or spring annuals (up to an average of 12 thrips per 25 cuttings in certain crops3). We repeated this research to find out which thrips were coming in on propagation material. Interestingly, we only found WFT.

This led us to suspect OT were breaking in from the outside. Sticky cards set up outside three greenhouse operations from spring to fall 2019 confirmed a consistent presence of OT directly outside Niagara greenhouses. OT represented about 15 per cent of the thrips caught on the cards, on average.

Why is this important? It turns out that when it comes to thrips species composition in your greenhouse, what happens outside can have a direct impact on what happens inside.

At our research sites, the greenhouse with the highest proportion of OT outside had consistent OT presence in their crop all year. The species composition in their crop was perfectly matched to what was happening outside, as well (Figure 1). Similarly, the greenhouse with the lowest proportion of OT outside had very few OT inside.

Figure 1.
Generally, the percentage of thrips that were OT caught outside on yellow sticky cards (yellow bars) seemed to reflect the percentage collected from the greenhouse crop inside (green bars).

However, outside pressure isn’t the only thing that can influence species composition. At our third research site, the proportion of OT in the crop was actually a lot higher than what we expected based on outside catches. This suggests that this greenhouse’s IPM program may be less effective for OT compared to other sites.

At all sites, though, we saw thrips populations for both species peak in July and August. So, if you want to prevent OT from becoming a problem in your greenhouse (and messing up your biocontrol program for WFT), this is a good time to go bananas with mass trapping! This is especially important for side-venting greenhouses, where thrips can more easily break in.

Catching Onion Thrips in the Act

Mass trapping, if used properly, can be an effective way of reducing the number of thrips that make it through your vents and into your crop.

You may have heard of study results from Europe that blue is the best card colour for trapping thrips. However, in 2016/17 trials looking at the efficacy of yellow versus blue sticky cards and tape in Ontario greenhouses, Dr. Jandricic found that yellow was better than blue for catching thrips, regardless of the manufacturer.4 But this research was done in greenhouses with predominantly WFT populations – what about OT?

To answer this, we put up yellow and blue sticky cards inside three potted chrysanthemum greenhouses throughout 2019. As it turns out, in addition to their love of chrysanthemums, OT and WFT also share a preference for yellow sticky cards (Figure 2). However, the strength of this preference can vary between greenhouses.

Figure 2.
When tested in chrysanthemum greenhouses, yellow sticky cards caught more thrips than blue cards. On average, 60% of thrips were caught on yellow cards, although this preference varied by site. At some sites, over 75% of thrips were caught on yellow, while at other sites it was closer to 50%.

Surveillance operation

Since sticky cards are used for monitoring as well as mass trapping, we also wanted to know how accurately sticky cards reflected the thrips species composition in the crop.

We collected thrips directly from the crop using plant taps and compared the ratio of OT to WFT with what was caught on the cards. Overall, when we looked at the averages throughout the growing season, the cards gave us a pretty accurate picture of thrips species composition in the crop. But, week to week there is a LOT of variation.

Unfortunately, this means that weekly monitoring cards aren’t a reliable tool when it comes to pest management decisions based on how many OT versus WFT you’ve got in your crop (i.e. to spray or not to spray). If you want to get a clear picture of what’s happening in your crop, you’ll need to collect thrips directly from the plants themselves.

Motive, Means & Opportunity

Although outside thrips prevalence plays a role in initial infestation, the differences in what OT and WFT do inside the greenhouse is where the trouble really starts.

You may notice that in late fall when it’s too cold for thrips to fly outside, WFT numbers start to steadily decline in the crop. We found that OT numbers, on the other hand, remain steady. They can even increase in number throughout the winter and early spring. Since there is no source of incoming OT (on cuttings or from the outside), this confirms that OT may be a more cunning adversary than WFT.

There are two possible explanations for why OT populations can increase over the winter/spring. Either 1) OT reproduce much faster than WFT on greenhouse crops, or 2) biocontrol-based IPM programs don’t work as well for OT as they do for WFT in cooler months.

Both thrips species have been well-studied by researchers all over the world, and there is no indication that OT has a faster reproductive rate than WFT. As for the efficacy of biocontrol products, a lot of literature, plus all of our laboratory tests to date (looking at predatory mites, microbial pesticides, and nematodes), indicate that the biocontrol products we currently use for WFT should work as well for OT – or maybe even better (see Figure 3)!

Figure 3.
Number of thrips larvae eaten by predatory mites and thrips adults eaten by Orius in lab trials. This data suggests that current biocontrol products should work for both OT and WFT.

The Mystery Continues…

We now understand who the new thrips villain is and where they come from, but so far we haven’t identified why they are able to evade our tiny police force of predatory mites and other biocontrol agents.

We’ve gathered plenty of evidence in the lab, so the next step will be to examine the scene of the crime. Which is to say we’re going to conduct greenhouse trials to see how OT, WFT and thrips biocontrol agents interact on plants. Maybe this will give us the clues we need to control OT without resorting to pesticides.

Stay tuned for installments of this gripping biocontrol mystery!

Which thrips are which?

Western Flower Thrips
Key features: Larger than the other yellow-coloured thrips you’ll encounter, WFT have bright red ocelli (three spots between their eyes). They also have plenty of long coarse hairs on the top and bottom of their “shoulders” (called the pronotum). WFT body colour ranges from common pale yellow to a very dark brown (called a “dark morph”).

Damage pattern: Widespread, dispersed damage in crop; frequently causes damage to flowers.

Onion Thrips
Key features: Pale grey ocelli (eye spots); coarse hairs occur only on the bottom of the pronotum (none on top); their bodies range in colour from pale yellow to brown. Smaller than WFT.

Damage pattern: Crops damaged in small clusters of plants; heavy damage to the foliage that makes the plant unsellable; less damage to flowers. 

Note: With the right gear (a microscope) anyone can learn how to identify the usual suspects that show up in their greenhouse. For an identification guide designed specifically for growers, go to http://greenhouseipm.org/pests/thripskey/ 

References

MacIntyre-Allen, J., C.D. Scott-Dupree, J.H. Tolman, C.R. Harris. 2005. Resistance of Thrips tabaci to pyrethroid and organophosphorous insecticides in Ontario, Canada. Pest Management Science 61: 809-815.

Summerfield, Ashley. 2019. Biocontrol thriving in Canadian floriculture greenhouses. Greenhouse Canada, March 26, 2019.

Buitenhuis, R., Lee, W., Summerfield, A., & Smitley, D. (2019). Thrips IPM in floriculture: cutting dips to start clean. IOBC-WPRS Bulletin, 147, 130–135.

Jandricic, S. 2019. Making mass trapping work for you. GrowerTalks, June 1, 2019.


Ashley Summerfield is a senior research technician in biological control at Vineland Research and Innovation Centre and an MSc. candidate at the University of Guelph. Sarah Jandricic, PhD is the greenhouse floriculture IPM specialist at the Ontario Ministry of Agriculture, Food and Rural Affairs. Ashley’s co-advisors on the onion thrips project are Rose Buitenhuis, PhD, (Biocontrol Lab; Vineland Research and Innovation Centre) and Cynthia Scott-Dupree, PhD, (Professor and Bayer Crop Science Chair in Sustainable Pest Management). Questions? Email Ashley at ashley.summerfield@vinelandresearch.com


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Anastatus against brown marmorated stink bug

Good feedback from an area within the Modena province for the first introductions of Anastatus bifasciatus. The Italfrutta cooperative carried out a first test in 2021 with small yet significant results.

“The test involved three companies, two specializing in pears and one in pears and stone fruit. We introduced Anastatus twice, in mid and late June for the businesses dealing with pears and earlier for that dealing with stone fruit. Insects were introduced at the edges, near a canal, in some woodland not far from the orchards. The purpose was to inoculate the antagonist insect and verify its effectiveness in this environment,” reports Sara Bellelli, Ital-frutta technician.

Anastatus launches in an archive photo

Analyses were carried out in September 2021 in collaboration with Bioplanet, revealing a parasitization of bug eggs between 20 and 30%, with an average of 25%.

“It is an encouraging result, as it was only a test year. It takes time for an antagonist insect to reach a balance with the harmful insect. In addition, we must add that there is not a lot of biodiversity in our territory, so the data is even more encouraging. We are considering not only to repeat the launches, but also to increase the businesses involved already in 2022.”

Anastatus bifasciatus as a native species, versatile and available in large quantities, remains an excellent option to intensify and accelerate the natural rebalancing process. In light of what could not be done with chemical treatments, also due to the lack of authorized molecules, biological control remain the most effective measure with the best cost/benefit ratio in cases of introductions of exotic parasites to a new area.

Publication date: Tue 22 Feb 2022

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FEBRUARY 14, 2022

Common plant disease found to defend its host against pests

by University of Turku

Common plant disease found to defend its host against pests
Ergot disease on the studied red fescue plants. Ergot is common on rye and some other cereals. It is toxic to humans and spoils the yields. However, it can be a beneficial protector for the plant. Credit: Benjamin Fuchs

Scientists from University of Turku observed that ergot, a common plant disease on rye, defended its host plant chemically against grass feeding insects. The ergot disease in grains spoils the yield and causes seed loss to the plant. Based on this, it is classified as harmful from the human perspective. A new study states that the ergot appears to be a beneficial protector for its host plant capable of even increasing plant fitness.

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On an experimental field at the University of Turku Subarctic research station Kevo, the research team studied fungal symbionts of grasses and their effects on plant biotic threats such as herbivorous aphids and ergot disease.

In the study, scientists used a widely distributed grass species, red fescue, and its fungal endophyte in the genus Epichloë. Fungal endophytes are fungi living entirely or part of their life cycle inside their host plants. This symbiotic relationship is commonly described as defensive mutualism which is characterized by plants providing nutrients to the fungus in exchange for protection against herbivory.

“Epichloë fungi are largely depending on their host plant for reproduction via the plant seeds. The fungal hyphae grows inside the plant up into the developing seeds, where it is spread to the developing new plant individuals. An endophyte like this would not survive without its host plant, which is why the plant wellbeing is in the interest of the symbiotic fungus,” explains doctoral candidate Miika Laihonen.

Endophyte symbiosis increased the ergot infections of plant seeds—but the plant might benefit

Common plant disease found to defend its host against pests
Hyphae of Epichloë fungus growing inside the tissues of grass seed. These fungi grow inside the plant and cannot be detected externally. Credit: Miika Laihonen

The team observed whether the fungal endophyte affected the occurrence of herbivorous insects and fungal ergot infections in the study plants. The ergot fungus causes the ergot disease in grasses, including cereals. Thereby, the plant loses few of its seeds to the disease. The ergot-contaminated grain is toxic to humans and the ergot fungus is an unwelcomed guest on farmlands.

The researchers found that pest insect occurrence was not directly affected by the fungal endophyte but the ergot was more commonly detected on the plants with a fungal endophyte. Further analyses revealed that aphids rarely colonized plants infected by the ergot fungus. Thus, the endophyte indirectly repelled aphid herbivores by promoting ergot symbiosis. This was supported by the chemical analysis of the plants.

“Our first impression was that the fungal endophyte was harmful for the plant as it increased the probability of the plant getting infected by the ergot fungus. When we realized that the aphids avoided the ergot, we saw the results in a new light. Possibly the benefits of the ergot outweight the harms,” Laihonen says.

This is not the only time the ergot was found to repel animals in nature. An earlier study found that grazing sheep were avoiding feeding the inflorescences from plants that were infected by ergot. Thus, hosting the ergot fungus provides protection for the majority of viable plant seeds and may ultimately be a fitness advantage for the plant and the associated Epichloë endophyte.

“As humans, we have a natural tendency to judge the organisms from our own point of view. However, by doing so, we can miss a bigger picture. We classify the ergot fungus as a harmful plant pathogen because that is what it is for us. For the plant though, it can be a savior: by occupying very few seeds, the ergot can safeguard the rest of the next plant generation,” explains Laihonen.


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More information: Miika Laihonen et al, Epichloë Endophyte-Promoted Seed Pathogen Increases Host Grass Resistance Against Insect Herbivory, Frontiers in Microbiology (2022). DOI: 10.3389/fmicb.2021.786619

Journal information: Frontiers in Microbiology 

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Tobacco Thrips: Tiny Insects With a Big Impact on Georgia Peanut Production

ENTOMOLOGY TODAY 

Tobacco thrips (Frankliniella fusca) also have a taste for peanut, and they spread the plant virus causing spotted wilt disease. A new guide in the open-access Journal of Integrated Pest Management details the biology and management of tobacco thrips in peanut crops. (Photo by Jena Johnson, University of Georgia Department of Entomology)

By Gabrielle LaTora

Gabrielle LaTora

Few people other than farmers think about the toll that insect-transmitted viruses have on crop yields. Tomato spotted wilt orthotospovirus (TSWV)—the virus that causes spotted wilt disease in peanut—caused over $27 million (US) in financial losses during the 2020 peanut season in the state of Georgia. Although TSWV infects several crops, it can be devastating for Georgia’s peanut growers, who produce more peanuts than any other state in the U.S.

Peanut plants with spotted wilt disease develop discolored leaflets and abnormal pods and kernels. Often, whole plants become stunted. The primary vector of TSWV in Georgia peanuts is the tobacco thrips (Frankliniella fusca). Besides transmitting TSWV, larvae and adults directly injure peanut plants when feeding, causing additional foliar symptoms and yield losses.

Thrips can be difficult to identify. Life stages of Frankliniella fusca on peanut are shown here: (A) egg; (B) first instar larva; (C) second instar larva; (D) prepupa; (E) pupa; (F) brachypterous adults, female (left) and male. (Scale bar = 0.5 millimeters). (Photos by Yi-Ju Chen and Pin-Chu Lai, Ph.D.)

In “Frankliniella fusca (Thysanoptera: Thripidae), the Vector of Tomato Spotted Wilt Orthotospovirus Infecting Peanut in the Southeastern United States,” published this month in the open-access Journal of Integrated Pest Management, my colleagues at the University of Georgia Vector-Virus Interactions Lab and I provide an overview of F. fusca‘s biology and pest status, including its morphology, life cycle, vector biology, management, and economic impact. Our hope is that this article can be used as a go-to for researchers, extension professionals, farmers, and anyone who wants to learn more about F. fusca. Thrips can be difficult to identify, so we have provided photos and descriptions of each F. fusca life stage and photos of short-winged and long-winged morphs.

Because peanut is an annual crop, F. fusca overwinter in weed hosts surrounding peanut fields until peanuts are planted again in the spring. Many of these plants are also TSWV hosts—F. fusca acquire TSWV as first- and second-instar larvae most likely by feeding on infected weeds before peanuts are available, then moving into croplands and inoculating peanuts in the late spring.

Using TSWV-resistant peanut cultivars has been the most common and successful non-chemical management strategy to date. Resistant cultivars are not immune to the virus, but they exhibit milder symptoms and higher yields than susceptible cultivars. Many growers employ avoidance and disruption strategies, too—they may shift planting dates to avoid peak thrips populations or modify planting patterns to disrupt thrips’ landing cues. Most growers also head off TSWV outbreaks by controlling thrips with prophylactic applications of insecticides, like phorate and imidacloprid. In addition to controlling thrips, phorate—an organophosphate—can actually suppress spotted wilt disease by inducing peanut defenses.

stunted peanut growth
spotted wilt disease foliar symptoms in peanut

Peanut Rx, a disease risk index developed by researchers and extension specialists from southeastern land-grant universities, is a tool used by growers to evaluate the risks of peanut diseases, including spotted wilt, on their farms. Peanut Rx uses individual farm and management characteristics, like plant density, row pattern, irrigation, pesticide programs, and prior disease incidence, to predict disease risks each year.

Although most Georgia peanut growers use a variety of methods to manage F. fusca and TSWV, there are still opportunities to diversify IPM programs. At this time, there are no standardized monitoring protocols or economic thresholds for F. fusca in peanuts. Very few studies have evaluated biological control agents, like thrips-parasitic nematodes and generalist predators, against F. fusca. Although TSWV-resistant cultivars are common, resistance to thrips themselves is not a targeted trait for peanut breeding programs. By “stacking” TSWV and thrips resistance traits, peanut cultivars can become even more resilient.

Read More

Frankliniella fusca (Thysanoptera: Thripidae), the Vector of Tomato Spotted Wilt Orthotospovirus Infecting Peanut in the Southeastern United States

Journal of Integrated Pest Management

Gabrielle LaTora is a research professional and lab manager at the Srinivasan Lab at the University of Georgia Griffin Campus in Griffin, Georgia. Twitter: @Gab_LaTora. Email: gabrielle.latora@uga.edu.

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 Frankliniella fuscaGabrielle LaTorageorgiaintegrated pest managementJournal of Integrated Pest Managementpeanuttobacco thripstomato spotted wilt orthotospovirus

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Opportunities for natural enemy to fight devastating fall armyworm

by CABI

Opportunities for natural enemy to fight devastating fall armyworm
Telenomus remus provides good opportunities for the establishment of an augmentative biological control program, reinforcing sustainable production of major crops such as maize in affected countries. Credit: G. Goergen, IITA

A new CABI-led review has highlighted mass rearing techniques, estimated costs of mass production and release strategies for the natural enemy Telenomus remus that suggests it could be effective in the fight against the devastating fall armyworm (Spodoptera frugiperda) in affected countries.

The study, published in CABI Agriculture and Bioscience, states how T. Remus has already been used against fall armyworm in the Americas for many years and is even effective against other species of the genus Spodoptera—all of which blight the crops of millions of smallholder farmers including the staple crop maize.

Fall armyworm is a significant pest of over 100 crops but favors maize. The recent CABI paper “Towards estimating the economic cost of invasive alien species to African crop and livestock production,” for example, estimates that in Africa the pest causes annual yield losses of around USD $9.4 billion.

Currently, in maize, the pest is predominantly controlled by pesticides or transgenic events. However, the use of biological control agents is considered the most sustainable and preferred method of control, providing high effectiveness. Among the various natural enemies reported for FAW, the egg parasitoid Telenomus remus has gained most interest.

Lead researcher Dr. Yelitza Colmenarez, Center Director at CABI’s center in Brazil, said, “There is no ready-to-use package available to advise farmers in using T. remus against fall armyworm and related pests. Further studies are urgently needed to precisely determine optimal release rates, release times and frequencies, number of release points, the best stage and device for releases and other aspects such as how large the fields should be to achieve efficient pest control.”

“However, high egg parasitism rates together with long-term evidence from Venezuela suggest that T. remus has indeed high potential to successfully suppress fall armyworm and related pests.

Opportunities for natural enemy to fight devastating fall armyworm
Maize infested by fall armyworm. Credit: CABI

“If biological control of FAW and related pests with T. remus should become a viable option, release rates may need to be more closely to rates used in the 1990s in Venezuela, i.e. rates of about 5,000–10,000 wasps per ha and season, unless major breakthroughs with cheaper mass production of the parasitoid are achieved.”

The review also suggests that releases for individual smallholder farmers owning little land may be inefficient, but on the other hand that regional approaches could work very well.

The scientists believe that—similar to other biological control agents in field crops—the use of T. remus will best be done as a part of an Integrated Pest Management program, avoiding broad spectrum insecticides in release fields. Both quality control of the mass reared parasitoid and an optimized, cost-efficient release strategy is crucial to a successful pest management, they say.

Dr. Colmenarez added, “Due to the recent invasion of fall armyworm in Africa, Asia, and Australia, T. remus provides good opportunities for the establishment of an augmentative biological control program, reinforcing sustainable production of major crops such as maize in affected countries.”

“When considering the use of biological control agents, it is always necessary to include an assessment of possible risks for non-target effects, particularly for exotic species. In most of those countries where T. remus may be considered for release in the future, the parasitoid has been found to be present, e.g. China, India, Australia and several African countries, so cannot be considered exotic there.”

“However, in regions where T. remus is not known from, its status should be carefully evaluated and appropriate risk assessment procedures followed. Altogether, T. remus releases may be having high prospects for contributing to FAW management in newly invaded areas though still challenges exist that would require further research.”


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More information: Yelitza Coromoto Colmenarez et al, The use of Telenomus remus (Nixon, 1937) (Hymenoptera: Scelionidae) in the management of Spodoptera spp.: potential, challenges and major benefits, CABI Agriculture and Bioscience (2022). DOI: 10.1186/s43170-021-00071-6

Provided by CABI

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‘Fungus-growing ants’

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Leaf-cutter ants: The insects that are farmed by fungi © BBC Studios

Leaf-cutter ants: The insects that are farmed by fungi

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Leaf-cutter ants are traditionally referred to as ‘fungus-growing ants’, but evolutionary biologist Dr Pepijn Kooij argues that we should call the mushrooms ‘ant-growing fungi’.

By Amy Barrett

Published: 07th February, 2022 at 04:00

Beneath the rainforests of South America lives a fungus that consumes 50,000 leaves a day without ever coming to the surface. It relies on ants to bring it food in exchange for nutrients. This unlikely partnership starred in Sir David Attenborough’s new wildlife series The Green Planet, available now on BBC iPlayer. Evolutionary biologist Dr Pepijn Kooij speaks to Amy Barrett about this special relationship.

The leaf-cutter ants rely on their fungus for food. Why don’t they just cut out the middleman and eat the leaves themselves?

Digesting plant material is a difficult process, even for us humans. It’s a hard thing to do.

Think about herbivores, carnivores and omnivores, and just look at, for example, the lengths of their intestines. If you take a tiger – a carnivore – the length of its intestines is about six metres. But if you look at a cow – the perfect example of a herbivore – the intestine is about 24 metres long, and cows also have multiple stomachs. It’s a long process to digest plant material, and you need lots of different bacteria to help you do it.

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Plants have this defence mechanism: an enormous cell wall around their cells to protect them from being eaten. It takes a lot of energy to get to the parts in the plants that we actually need – the nitrogen and proteins. But there are specialised organisms, such as bacteria [in a cow’s stomach], that are designed to do that kind of work. For the ants, they want those proteins, but it’s very hard for the insects to actually extract them. So they have their fungus help penetrate the cell, then the ants feed on the fungus.

Sir David Attenborough in The Green Planet

Sir David Attenborough takes you into the surprising world of plants, trees and fungi in The Green Planet © BBC Studios

But doesn’t the fungus need the protein? Why would it share?

Well, the fungus takes some of the proteins, but it has developed this relationship with the leaf-cutter ants. The fungus grows specialised organs, which we call gongylidia. Inside the gongylidia are fats and proteins, which are nutritious for the ants. The ants eat these gongylidia.

But the fungus also benefits from this relationship. Usually, fungi need to release enzymes that let them break down plants to absorb the nutrients. With the leaf-cutter ant partnership, the fungus fills its gongylidia with enzymes. The ants eat these enzymes when they feed on the gongylidia, but they cannot digest them, so they are still active when the ants poo them out.

The ants will bring new plant material into the nest, place it on the fungus and then poo on top. This gets the fungal enzymes exactly where they need to be to break down the plants. The fungus is using the ants like trucks, to transport the enzymes from one part of the fungus to the place where the new plant material is located.

If you watch the first episode of The Green Planet, you’ll notice the fungus looks like a big ball. This ball is the fungus, made up of what’s called the mycelium.

These organisms are often called fungus-growing ants, but I think ant-growing fungi could be a better term.

Read more about fungi:

Ant-growing fungi?

So, ‘fungus-growing ants’ is term that the Royal Botanic Gardens, Kew, first used in the late 19th Century for these ants that farm fungi as their main food source. I’ve been trying to change the view more into ant-growing fungi.

This is a mutualism, and a mutualism has a benefit for both [parties]. To say that the ants are growing the fungus is a bit one-sided. Of course, they bring in the leaves and they grow the fungus on there. But the fungus is also directing and giving assignments to the ants somehow, using chemical communication. So you could also see it as ant-growing fungi.

It’s as if the fungus is using the ants, sort of like cattle. Seeing the system that way brings up lots of different questions. Our research is trying to untangle this whole system to see how it works. Because in the end, it’s a mutualism and you could even see that as one big organism.

In the same way, we humans have lots of bacteria in our guts, but we still see ourselves as one system. We wouldn’t say we are a human and bacteria. So in that sense, it’s not ants that grow fungus, it’s ants and fungus together.

You said the ball was mycelium. What is that?

You might’ve seen fungi in the form of a mushroom, but this is only a small percentage of the actual organism.

In a forest in England, for example, you might see mushrooms, but there will be metres and kilometres of mycelium underneath the soil that you don’t see.

This mycelium is much more important [than the mushroom] for the fungus. In fact, the mycelium is the actual fungus. The mushroom is only a sexual reproduction tool.

The best comparison you might make is something like an apple tree, with the apple that contains its seeds, or a plant’s flower and its pollen. So, the mushroom is then analogous to the flower and it creates the spores, which are like the pollen.

It’s only that small part of the fungus, the mushroom, that you actually see, which
is the most pretty part, of course. Though mycelium can look very pretty – I can tell you that with certainty. But in general, you can’t see the mycelium because it’s very thin, thread-like structures in the soil.

It’s the mycelium that extracts all the nutrients. It does all the hard work. And then bubbles together to form the mushroom.

Leaf-cutter ants and fungi

Leaf-cutter ants share their colonies with a fungus, which they cultivate with the leaves they retrieve © Getty Images

Why don’t the ants just eat the mushroom?

Normally, this particular fungus doesn’t need to grow mushrooms for sexual reproduction, because the ants help spread the fungus.

Every generation of ants begins with a new queen, and the new queens will take a piece of the fungus into a special cavity in their mouth that they take away when they fly out to mate and start a new colony.

This is a process we call ‘vertical transmission’. It makes sure that there is a continuation of this particular strain of fungus without any genetic mixing.

Producing a mushroom requires a lot of energy that is wasted on something that’s unnecessary. Also, the ants can’t eat the mushrooms.

When I studied these [fungi] species in Copenhagen, we kept them in climate-controlled rooms. Sometimes the climate chambers had problems – a sudden decrease in temperature, or the humidifier might not be working very well – and we would get mushrooms. The ants would attack those mushrooms. They would cut away at the lamellae [gills] on the underside of the mushroom cap, where the spores are formed, and try to get rid of the mushrooms.

Now, in the campus where I am in Brazil, every now and then we see mushrooms coming up. It’s very, very strange to see. One of the PhD students that I started working with at São Paolo State University, Rodolfo Bizarria Jr, started counting how many times we saw this.

Then we went back through the literature to find all the occurrences [of mushrooms appearing]. There aren’t many, going back all the way to the 19th Century. But we can see an increase. We tried to determine whether there was a correlation with the temperature, the humidity and the precipitation, and there does seem to be a link.

Dr Pepijn Kooij

Dr Pepijn Kooij has been studying how leaf-cutter ants and fungi have formed a mutualism © BRG Kew

Could climate change affect these species?

We don’t know yet. We just know there is an increase in mushrooms, and normally this is not profitable for the system. We would have to look into if this is going to be really detrimental for the colony.

Where is this fungi-ant system found?

Only in the Americas. So, you can find fungus-growing ants in the southern parts of South America, around Argentina and Chile, all the way up to the southern parts of the United States – Florida, Arizona, Texas. Even on the Caribbean islands you can find some of these species.

Why did this relationship begin?

That’s the big question. We don’t know. There are several different theories, and the most common is that it might have originated from ants that started collecting plant material as food. The ants deposited the material inside the nest chambers and then a fungus started growing on it, and somehow they realised, “Hey, this is nice!”

Kind of like how we discovered how to make beer, for example, or other alcoholic products, because fungi started growing on our rotting food and eventually we realised, “Oh, but that’s actually very nice.”

But the exact connection, we don’t know for sure. We know more about the ants because people have studied them more. So we’re much closer to understanding the ant ancestors than when we started doing this.

We don’t know what the closest ancestors of these fungi are. A key part of my research is trying to find that out and trying to understand why these ants chose this fungus and not another one. What is so good about these fungi and what is the origin of the fungus that is related to it, those that aren’t growing with ants? Once we know that we might be able to compare the genomics and the ecology. With that, at least, we can make some inference of how this all started.

But this isn’t just a relationship between ants and fungi. How have the plants adapted to protect themselves from being eaten?

Plants have their own defences, and they’re not necessarily particular to these ants, but a general protection against herbivores. One way they do this is by producing toxins, which we call phenolic compounds. Tannins are an example for that. So, if you have a nice glass of wine, the tannins in your mouth – the drying, bitter taste – are the defence mechanism of plants.

That acidity is very good at fending off any fungi, any bacteria – and with that any herbivores, because it would disrupt their microbiome.

However, another defence is other fungi. Inside plant leaves you’ll find what we call endophytes. These are fungi that form, in most cases, a mutualism with the plant, to protect it against herbivores. They would not like to have other fungi in their food!

Studies with leaf-cutting ants showed that when presented with leaves infected with endophytes, the ants would always go for the leaves that had the least. Because otherwise you might get competition between their fungus and the fungi in the leaf.

Leaf-cutter ants collecting leaves

Left-cutter ants have a mutually beneficial arrangement with fungi, which does the hard work of digesting leaves for them © BBC Studios

How do they know?

Good question. We think that the ants can smell it. They don’t have noses, of course, but with their antennae they’re able to pick up odours, chemicals and volatiles released by the plants or coming from the fungus. That’s another way the fungus communicates with its ant colony. The ants might give something to the fungus and the fungus can give off a signal that says, “I don’t like this one.”

Studies by a group in Germany gave the ants little pieces of leaves treated with fungicides. After 24 hours, the ants stopped bringing those to the fungus. It’s not that the ants that recognised the fungicide, but they recognised something was wrong because the fungus was not liking it. There’s a really tight interaction between the fungus and the ants.

Read more about insects:

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